Summary: | Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2003. === Includes bibliographical references (p. 83-86). === In this thesis, I present an experimentally proven control methodology for the autonomous execution of aerobatic maneuvers with small-scale helicopters, and a low-order dynamic model which adequately describes a miniature helicopter in a wide range of flight conditions, including aerobatics. The control laws consist of steady-state trim trajectory controllers, used prior to, and upon exit from the maneuvers; and a maneuver execution logic inspired by human pilot strategies. In order to test the control laws, a miniature helicopter was outfitted with a custom digital avionics system, and a hardware-in-the-loop simulation was developed. The logic was tested with several aerobatic maneuvers and maneuver sequences, which demonstrated smooth maneuver entry, automatic recovery to a steady-state trim trajectory, and robustness of the trim-trajectory control system toward measurement and modeling errors. Based on these results, I further propose a simplified hybrid model for a helicopter under such closed loop control. The model can be utilized in the development of computationally tractable motion-planning algorithms for agile vehicles. === by Vladislav Gavrilets. === Ph.D.
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