Stability and Performance of an Undersea Kite Operating in a Turbulent Flow Field

• Published in: IEEE transactions on control systems technology 2023-07, Vol.31 (4), p.1-16
• Main Authors: Reed, James, Abney, Andrew, Mishra, Kirti D., Naik, Kartik, Perkins, Edmon, Vermillion, Chris
• Format: Article
• Language: English
• Subjects: Analytical models; Asymptotic stability; Autonomous underwater vehicles; Degrees of freedom; Disturbances; Energy harvesting; Flow stability; Frequency analysis; Frequency domain analysis; HYDRO ENERGY; Kinematics; Kites; Orbital stability; Orbits; Path tracking; Power generation; Stability analysis; System Validation; Trajectory; Turbines; Turbulence; Turbulent flow; Undersea
• ISSN: 1063-6536; 1558-0865
• DOI: 10.1109/TCST.2023.3237614

In this article, we examine the effects of flow disturbances resulting from turbulence on the dynamic behavior of an underwater energy-harvesting kite system that executes periodic figure-8 flight. Due to the periodic nature of the kite's operation, we begin by assessing orbital stability using the Floquet analysis and stroboscopic intersection analysis of a Poincaré section, with the former analysis performed on a simplified "unifoil" model and the latter performed on a six-degree-of-freedom (6-DOF)/flexible tether model. With periodic stability established, a frequency-domain analysis based on a linearization about the kite's path is used to predict the quality of flight path tracking as a function of the turbulence frequency. To validate the accuracy of these simulation-based predictions under flow disturbances, we compare the predictions of the kite's behavior against the results of small-scale tow testing experiments performed in a controlled pool environment.