Experimental validation of an airborne wind energy simulator based on a semi-empirical aerodynamic model
Creators: name: delosRíos-Navarrete, Francisco
name: Castro-Fernández, Iván
name: Cavallaro, Rauno
name: Sánchez-Arriaga, Gonzalo
Publisher: name: Zenodo
Year: 2023
Subjects: Airborne Wind Energy
test flight
experimental
simulation
AWE
AWES

description: Trustworthy aerodynamic models play a crucial role in the research of Airborne Wind Energy (AWE) systems because they are a fundamental block of the numerical tools that are used to develop and study novel control strategies and design efficient systems while minimizing the need for field testing. Diverse models have been proposed, with varying degrees of compromise between accuracy and computational cost. In particular, a model based on a three-dimensional Unsteady Panel Method was recently proposed as a reasonably accurate alternative with relatively small computational costs [1], and has been extended to include dynamic stall [2]. However, the tuning of the static and dynamic parameters in the dynamic stall model, as well as the validation of the numerical tool as a whole, requires extensive experimental data and analysis work.<br> <br> This work obtained abundant experimental data from a flight campaign using the improved UC3M testbed for a three-line Rigid-Framed Delta Kite [3], as depicted in Figure 1. This system features a variety of sensors for real-time measuring of the kite’s position, velocity, attitude and angular velocity, as well as tether tensions and the wind velocity vector, such as a high-precision RTK GPS system and a three-camera visual motion tracking system based on an artificial neural network. The full aerodynamic velocity vector is measured insitu by using a multi-hole pitot tube [4]. Additionally, and aimed at the tether model validation, a set of lightweight load cells have been boarded on the kite and attached to each tether. These sensors, together with the load cells installed on the Ground station, allowed to measure the tether tensions at both tether tips. This testbed can be operated both manually or using its real-time closed-loop controller, currently based on the combination of a PID controller for path-tracking and a waypoint strategy for guidance, as proposed by several authors in past studies [5][6].<br> <br> The experimental data have been used to validate an in-house AWE simulator for 3-line kites. The simulator uses the aforementioned aerodynamic model and a lumped-mass tether model. Its closed-loop controller module is identical to the one implemented on the testbed. The modeled system can also be directly commanded using logged actuator data from the testbed. This characteristic was used to first tune the parameters of the aerodynamic model and then to compare the experimental and simulation results.
description: Video from slide 7 is available at https://youtu.be/ZAFQkyRfJtU This work is being supported by the following grants: → PID2019-110146RB-I00. Modelling and flight testing of airborne wind energy and traction systems (GreenKite-2) Agencia Estatal de Investigación (Ministerio de Ciencia, Innovación y Universidades) → IND2022/AMB-23521. Ground-Actuated Airborne Wind Energy System Demonstrator (Industrial PhD – CT Ingenieros). Comunidad de Madrid (Consejería de Educación y Universidades)
description: {"references": ["Castro-Fern\u00e1ndez, I., et al.: Three-Dimensional Unsteady Aerodynamic Analysis of a Rigid-Framed Delta Kite Applied to Airborne Wind Energy. Energies 14 (23), (2021)", "Castro-Fern\u00e1ndez, I., et al.: A Semi-Empirical Aerodynamic Model Based on Dynamic Stall for Rigid-Framed Delta Kites during Figure-of-Eight Maneuvers. Airborne Wind Energy Conference (AWEC 2021). Conference paper (2022)", "delosR\u00edos-Navarrete, F., et al.: Status of UC3M Testbed for the Aerodynamic Characterization of Kites Applied to Airborne Wind Energy Systems. Airborne Wind Energy Conference (AWEC 2021). Conference paper (2022)", "Borobia-Moreno, R., et al.: Identification of kite aerodynamic characteristics using the estimation before modeling technique. Wind Energy. 24(6), 596-608 (2021)", "Fagiano, L. et al.: Automatic Crosswind Flight of Tethered Wings for Airborne Wind Energy: Modeling, Control Design, and Experimental Result. IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY (2014)", "Fechner U. and Schmehl R.: Flight Path Control of Kite Power Systems in a Turbulent Wind Environment. 2016 American Control Conference (ACC) (2016)"]}