Print Email Facebook Twitter Time Delay Margin Analysis for Model Reference Adaptive Flight Control Laws Title Time Delay Margin Analysis for Model Reference Adaptive Flight Control Laws: A Bounded Linear Stability Approach and Application to Aeroservoelasticity Models Author Melo Pacheco, Alexandre (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Delft Center for Systems and Control) Contributor Keviczky, T. (mentor) Degree granting institution Delft University of Technology Programme Mechanical Engineering | Systems and Control Date 2018-11-15 Abstract Adaptive control theory and the aerospace industry share a long and bountiful history which has led to innovative developments within modern control theory as well as the boldest industry promises for future generations of aircraft. Unfortunately, as we venture into the realm of adaptive control, commonly used robustness metrics, such as the phase margin, are lost. This fact, in addition with the lack of a well-established framework for control design, validation and verification raises an issue known as the certification problem of adaptive control. Oftentimes, theory can only take us as far as guaranteeing stability under limited conditions. The next step would be to develop quantifiable margins, or metrics, which can be translated into certifiable terms.A 2010 NASA study titled “Elastically Shaped Future Air Vehicle Concept” [1] pushes the aerospace industry towards fuel efficiency and the integration of lighter composite materials for new generations of aircraft. In turn this leads to flexible designs that show higher wing tip deflections and oscillations. A novelty control surface architecture – the Variable Camber Continuous Trailing Edge Flap (VCCTEF) – is being developed to assist in active flutter suppression and enable wing shaping control in order to improve cruise flight efficiency.The work developed in this thesis and during an internship working with the Adaptive Control and Evolvable Systems (ACES) team at NASA Intelligent Systems Division revisits the certification problem of adaptive control in the aerospace industry within the context of the VCCTEF project. In particular, we focus the time delay margin as an inherently critical stability metric for flight adaptive control and integrate time domain estimation methods with simulation driven certificates into an hybrid framework to create a linear moving time window model – the Bounded Linear Asymptotic Stability (BLAS) model for Model Reference Adaptive Control (MRAC) flight software used by the ACES team, including the Optimal Control Modification (OCM) introduced to guarantee transient response characteristics. Alternative time domain methods such as the Lyapunov-Krasovskii (L-K) are implemented in a Sum-of-Squares (SOS) framework for revision and discussion. To reference this document use: http://resolver.tudelft.nl/uuid:fe50967f-1ea4-4a4d-a9ce-1b138e3c8cf4 Part of collection Student theses Document type master thesis Rights © 2018 Alexandre Melo Pacheco Files PDF APacheco_Thesis.pdf 10.78 MB Close viewer /islandora/object/uuid:fe50967f-1ea4-4a4d-a9ce-1b138e3c8cf4/datastream/OBJ/view