Optimal Design of Excitation Inputs for Identifying the Dynamics of Fixed-wing Aircraft Considering Active Control in MIMO Systems

Abstract

This study presents a systematic and optimal framework for designing excitation inputs for fixed-wing aircraft system identification, with a particular focus on multi-input multi-output (MIMO) systems under active flight control. Excitation signals such as pulse, doublet, and multi-step are commonly selected due to their simplicity and widespread use in practical applications. However, their selection is often empirical and may not provide optimal excitation for accurate and robust parameter estimation. The proposed methodology systematically determines the most effective input signals, designs their frequency content and amplitude characteristics, and evaluates their performance under both open- and closed-loop control conditions. This approach facilitates accurate parameter estimation across multiple identification techniques and is generalizable to other aircraft as well as potentially to other complex dynamic systems. The effectiveness of the proposed method is demonstrated through high-fidelity six-degree-of-freedom (6-DOF) simulations in MATLAB/Simulink, showing its capability to efficiently and accurately excite the relevant aircraft modes for precise model identification. © 2026 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.