@inproceedings{042780a4ae344fd2be2a4405ec864bc4,
title = "Load alleviation control using dynamic inversion with direct load feedback",
abstract = "This paper addresses the use of dynamic inversion with direct load feedback to provide combined load alleviation and flight control of rotorocraft. The method is applied to a compound utility rotorcraft with similar airframe properties as a UH-60A along with a lifting wing. The controller makes use of flaperons and horizontal stabilizer in addition to the conventional main rotor / tail rotor blade pitch controls to track pilot commands while also minimizing pitch link loads. The nonlinear simulation is developed in FLIGHTLAB{\textregistered} with structural models of the rotor blades and control system. This model must be linearized to a linear time-invariant (LTI) system to support linear Dynamic Inversion control design. The vehicle dynamics and critical fatigue load are modeled with a linear time-periodic (LTP) model which is converted via harmonic decomposition into a high-order LTI model. This model is then reduced to design controllers across a range of airspeeds. The controllers are tested both in linear model simulations and using the full nonlinear FLIGHTLAB{\textregistered} model. The results show that the load alleviating controller achieves significant reduction in the pitch link peak-to-peak loads with minimal change in response characteristics, indicating that load alleviation can be achieved with no degradation in handling qualities.",
author = "Mariano Scaramal and Horn, {Joseph F.} and Umberto Saetti",
note = "Publisher Copyright: Copyright {\textcopyright} 2021 by the Vertical Flight Society. All rights reserved.; 77th Annual Vertical Flight Society Forum and Technology Display: The Future of Vertical Flight, FORUM 2021 ; Conference date: 10-05-2021 Through 14-05-2021",
year = "2021",
language = "English (US)",
series = "77th Annual Vertical Flight Society Forum and Technology Display, FORUM 2021: The Future of Vertical Flight",
publisher = "Vertical Flight Society",
booktitle = "77th Annual Vertical Flight Society Forum and Technology Display, FORUM 2021",
}