Thermal Energy Extraction Methods for UAV Gliders

Abstract

An aircraft’s flight-time is restricted by its fuel capacity or battery life. This senior design project explores the benefits of extracting energy from the environment for a small, unmanned aerial vehicle (UAV), specifically focusing on static soaring and solar energy extraction. Soaring is accomplished by using thermals (sections of rising air created by solar radiation and terrain fluctuations) to obtain lift. This project focuses on simulation of a thermal to observe the effects of a thermal on an aircraft, development of control algorithms to utilize lift from the thermal, and integration of these algorithms with the ArduPilot Mega 2.5+ open source autopilot software and hardware. Software simulations in MATLAB and hardware-in-the-loop simulations in FlightGear were both used to develop the control algorithms that enhanced the original ArduPilot code to detect and capitalize upon rising air. These algorithms were then tested in real-time flights. Furthermore, direct solar energy was also extracted through the employment of solar panels in a custom-built glider. The combination of harvesting direct solar power to sustain the flight computer along with using efficient thermal detection algorithms to stay afloat enables the aircraft to soar for an extended duration while unhindered by a dependence on nonrenewable energy resources.