Development and Field Testing of an Autonomous Soaring System

Open Access
- Author:
- Depenbusch, Nathan Thomas
- Graduate Program:
- Aerospace Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- November 02, 2017
- Committee Members:
- Jacob Willem Langelaan, Dissertation Advisor/Co-Advisor
Jacob Willem Langelaan, Committee Chair/Co-Chair
Joseph Francis Horn, Committee Member
Sean N Brennan, Committee Member
Constantino Manuel Lagoa, Outside Member - Keywords:
- autonomous soaring
aerial robotics
thermal soaring
soaring
unmanned aerial vehicle
UAV - Abstract:
- Autonomous soaring has the potential to greatly improve both the range and endurance of small robotic aircraft. This dissertation lays out an architecture for autonomous soaring that allows an aircraft to seek, detect, and exploit lift effectively. The enabling feature in this architecture is the generation of a dynamic map of lift sources (thermals) in the environment and the ability to use this map for on-line flight planning and decision making. Components of the autonomy algorithm include thermal mapping, explore/exploit decision making, navigation, optimal airspeed computation, thermal centering control, and energy state estimation. A finite state machine manages the aircraft behavior during flight and determines when changing behavior is appropriate. A complete system to enable autonomous soaring is described with special attention paid to practical considerations encountered during flight testing. This dissertation then presents the results of a test flight campaign conducted in an effort to demonstrate the developed system. Flight tests were conducted at the Aberdeen Proving Ground during Fall 2015 which resulted in 7.8 hours flight time with the autonomous soaring system engaged, with three hours spent climbing in thermals. Frequent observations of groups of birds thermalling with the aircraft indicate that it was effectively exploiting available energy.