Dissertations and Theses 2016 A Biomimetic, Energy-Harvesting, Obstacle-Avoiding, Path- Planning Algorithm for UAVs Snorri Gudmundsson Follow this and additional works at: https://commons.erau.edu/edt Part of the Automotive Engineering Commons, and the Mechanical Engineering Commons Scholarly Commons Citation Gudmundsson, Snorri, "A Biomimetic, Energy-Harvesting, Obstacle-Avoiding, Path-Planning Algorithm for UAVs" (2016). Dissertations and Theses. 306. https://commons.erau.edu/edt/306 This Dissertation - Open Access is brought to you for free and open access by Scholarly Commons. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. A BIOMIMETIC, ENERGY-HARVESTING, OBSTACLE-AVOIDING, PATH-PLANNING ALGORITHM FOR UAVs A DISSERTATION SUBMITTED TO THE DEPARTMENT OF MECHANICAL ENGINEERING AND THE COMMITTEE ON GRADUATE STUDIES OF EMBRY-RIDDLE AERONAUTICAL UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Snorri Gudmundsson 2016 © Copyright by Snorri Gudmundsson, 2016 All Rights Reserved ii THIS PAGE INTENTIONALLY LEFT BLANK iv ABSTRACT This dissertation presents two new approaches to energy harvesting for Unmanned Aerial Vehicles (UAV). One method is based on the Potential Flow Method (PFM); the other method seeds a wind-field map based on updraft peak analysis and then applies a variant of the Bellman-Ford algorithm to find the minimum-cost path. Both methods are enhanced by taking into account the performance characteristics of the aircraft using advanced performance theory. The combined approach yields five possible trajectories from which the one with the minimum energy cost is selected. The dissertation concludes by using the developed theory and modeling tools to simulate the flight paths of two small Unmanned Aerial Vehicles (sUAV) in the 500 kg and 250 kg class. The results show that, in mountainous regions, substantial energy can be recovered, depending on topography and wind characteristics. For the examples presented, as much as 50% of the energy was recovered for a complex, multi-heading, multi-altitude, 170 km mission in an average wind speed of 9 m/s. The algorithms constitute a Generic Intelligent Control Algorithm (GICA) for autonomous unmanned aerial vehicles that enables an extraction of atmospheric energy while completing a mission trajectory. At the same time, the algorithm automatically adjusts the flight path in order to avoid obstacles, in a fashion not unlike what one would expect from living organisms, such as birds and insects. This multi-disciplinary approach renders the approach biomimetic, i.e. it constitutes a synthetic system that “mimics the formation and function of biological mechanisms and processes.” v ACKNOWLEDGMENTS It would have been impossible to complete this work without the help of my dissertation committee. First, I would like to express my appreciation to Dr. Charles Reinholtz, the Chair of the ERAU Mechanical Engineering department. Serving as the PhD committee chair, Dr. Reinholtz’ friendly and helpful demeanor was not just exemplary, but made the long winding road toward my PhD considerably less bumpy. I am also greatly indebted to both Dr. Sergey Drakunov and Dr. Vladimir Golubev. Dr. Drakunov was the committee’s first advisor, but also mentored me in the pursuit of my goal. His expertise in mathematics and control theory was crucial in helping me evaluate the merits of the research presented in this dissertation. I am very grateful for his continuous encouragement of the research presented in this work. Dr. Golubev joined the committee later, but immediately became instrumental in pushing me to publish a portion of the work in conference and journal papers. He provided me with key guidance in those areas, something for which I am very thankful. In the capacity of his research background, Dr. Golubev also offered many insightful ideas that were incorporated in the dissertation. Additionally, I express my great appreciation and thanks to my committee members, Dr. Patrick Currier and Dr. Eric Coyle, both from the ERAU Mechanical Engineering department. I was heartened by the realization that each expressed a deep interest in the problem presented in my research. Their strong understanding of trajectory planning and obstacle avoidance theory helped cement these key areas in the dissertation. Words cannot express my gratitude for your support in making this dissertation a reality. Finally, I want to express my gratitude to the former and current chairs of ERAU’s Aerospace Engineering department, Dr. Habib Eslami and Dr. Tasos Lyrintzis. I also want to express my most sincere thanks to the current Dean of the College of Engineering, Dr. Maj Mirmirani, for extending the opportunity to complete my PhD in Mechanical Engineering. vi DEDICATION I decided long ago that, should I ever complete a degree of PhD, I would dedicate my dissertation to three individuals who profoundly impacted my life and approach to aviation. All three were pilots and, sadly, have passed on. First, there is the late Guðmundur Daði Ágústsson (1956-2016), a fellow Icelander, who first introduced me to the operation of real aircraft by inviting me, an eager teenage aircraft enthusiast, on countless flying trips in the mid 1970s. The exposure to real aircraft was enhanced by the myriad of questions regarding aviation that we bounced between us, many of which we were unable to answer. More than anything, this experience reinforced my determination to seek a scientific understanding of the physics of flying. Second, there is the late Colonel USMC, Robert Overmyer (1936-1996). I worked with Col. Overmyer as a flight test engineer early in my career, during the development of the Cirrus SR20 aircraft. It is impossible to describe the honor of having an opportunity to work with such an experienced aviator. Col. Overmyer was hands down the best pilot with whom I ever had the opportunity to fly. Not only had he flown all the century-series fighters and contemporary fighters in the US arsenal, he also had two space shuttle missions under his belt (STS-5 and STS-51B), as a first officer and pilot-in-command. In spite of this experience, he was both modest and amicable. Tragically, Col. Overmyer died on March 22 nd 1996 in the crash of an experimental aircraft he was flight testing. Third, there is the late Major Scott Anderson (1965-1999), described in Wikipedia as “… a late 20th- century American polymath: Air National Guard F-16 pilot, instructor pilot, general aviation test pilot, Flight Operations Officer, engineer, inventor, musician, football player, outdoor adventurist, and award winning author.” I worked with Maj. Anderson, also as a flight test engineer, during the development of the Cirrus SR20, from 1996-1999. He had taken over Col. Overmyer’s position. He was an extremely capable individual, with a perpetual smile that would light up a room. Sadly, Maj. Anderson died while performing a routine flight test on the first production example of the SR20 on March 23 rd 1999. vii TABLE OF CONTENTS 1. Introduction ........................................................................................................................1 1. 1 The Focus of the Dissertation ................................................................................................... 2 1. 2 Nature’s Extraordinary Machines ............................................................................................. 4 1. 3 Fundamentals of Soaring Flight .............................................................................................. 10 1.3.1. Sailplane Fundamentals .................................................................................................. 11 1.3.2. Operation of Sailplanes .................................................................................................. 12 1.3.3. Sailplane Airfoils ............................................................................................................. 14 1. 4 Software Development .......................................................................................................... 16 1. 5 Features of the GICA .............................................................................................................. 18 1.5.1. Basic Operation of the GICA............................................................................................ 18 1.5.2. Application of GICA in Large Aircraft ............................................................................... 21 2. A Survey of Literature........................................................................................................23 2.1 Path Planning and Obstacle Avoidance Algorithms ................................................................. 23 2.2 Gliding Flight .......................................................................................................................... 28 2.3 Atmospheric Modeling ........................................................................................................... 30 2.4 Energy Harvesting .................................................................................................................. 36 3. A Survey of Automation Technology for sUAVs ................................................................49 3.1 UAV Technology ..................................................................................................................... 51 3.2