Modeling and Simulation of Flight Profile and Power Spectrum for Near-Space Solar-Powered UAV

Abstract

Currently, several solar-powered unmanned aerial vehicles (UAVs) have achieved 24 h uninterrupted cruise. However, models that can cruise for weeks or even months without interruption are in the minority. The technological progress requires the improvement of subsystems and also depends on the accurate planning of flight profile and power spectrum in a long working cycle. Combined with the test data obtained during the development of a solar-powered UAV, this paper establishes systematic mathematical and physical models of aerodynamic, energy, and propulsion systems, which can reflect the change in performance parameters with flight conditions and the performance attenuation with time. Further, a track control strategy based on the principle of maximum energy utilization is proposed, and the energy balance model of each flight stage is established. On the basis of the strategy, the typical flight profile and power spectrum of a solar-powered UAV are analyzed. Finally, the input parameters are decomposed into task parameters (takeoff time window, flight season, flight latitude, takeoff weight) and performance parameters (lift–drag ratio, secondary battery density), and their effects on mission feasibility are studied respectively. The research methods and conclusions of this paper have reference significance for the mission and track planning of solar-powered UAVs.

Development of an Automatic Solar Tracker Control System for a Tandem-Winged UAV and Its Implementation Strategies

“…This allows the drone to switch between solar power and other sources of energy as needed, depending on the availability of sunlight and the power usage of the vehicle. Another alternative, used in vehicles such as the Zephyr drone, is to optimize the flight path in a way that can maximize the amount of sunlight it receives [10][11][12]. Furthermore, attitude optimization can also be employed, where the vehicle orients its wing planform towards the sun and maximizes the amount of sunlight that the panels receive to improve their efficiency.…”