OPTIC FLOW BASED STATION-KEEPING AND WIND REJECTION FOR SMALL FLYING VEHICLES

Title of thesis: OPTIC FLOW BASED STATION-KEEPING AND WIND REJECTION FOR SMALL FLYING VEHICLES Bryan Patrick, Masters of Science, 2010 Thesis directed by: Professor J. Sean Humbert Department of Aerospace Engineering Optic flow and Wide Field Integration (WFI) have shown potential for application to autonomous navigation of Unmanned Air Vehicles (UAVs). In this study the application of these same methods to other tasks, namely station-keeping and wind rejection, is examined. Theory surrounding optic flow, WFI and wind gust modeling is examined to provide a theoretical background. A controller based on a H∞ bounded formulation of the well known Linear Quadratic Regulator in designed to both mitigate wind disturbances and station-keep. The performance of this controller is assessed via simulation to determine both performance and trade-offs in implementation such as the method for optic flow calculation. Furthermore, flight tests are performed to examine the real world effectiveness of the controller. Finally, conclusions about potential improvement to implementation are drawn. OPTIC FLOW BASED STATION-KEEPING AND WIND REJECTION FOR SMALL FLYING VEHICLES by Bryan Patrick Thesis submitted to the Faculty of the Graduate School of the University of Maryland, College Park in partial fulfillment of the requirements for the degree of Masters of Science 2010 Advisory Committee: Professor J. Sean Humbert, Chair/Advisor Professor Robert M. Sanner Professor Inderjit Chopra c © Copyright by Bryan Patrick 2010 Acknowledgments It is impossible to fit all the people that deserve thanks in a scant page. I hope I can fit most of you. My family whom have always been supportive deserve many thanks for their love and support. Mom, Dad, I know I have neither called nor came home as much as either of you would have liked but I am grateful to and love you both. Thanks to all my lab-mates in the Autonomous Vehicles Lab. Thanks to David McLaren for helping me make AVLSim, Greg Gremillion for quadrotor piloting, Kedar Dimble and Imraan Farque for letting me bounce ideas off you guys, Andrew Hyslop and Joe Conroy for the help and advice, Renee Campbell and Steve Gerardi for bearing interruptions caused by the flight tests, Jishnu Keshavan for finding the journal paper I needed and Badri Ranganathan for spotting my simple math mistakes. Also to thank are all those friends who have helped in ways that they may not even have realized. Chris Wilson, I remember all those late nights watching you give 110% that finally lead to you getting your degree. Thanks for the example you set. Of course, Dr. Humbert thank you for guiding me through graduate school these past couple years and most of all for convincing me that I could get into the program despite my mediocre GPA. Finally and most importantly, thanks be to God, without whom all is meaningless.