Rotary Wing Final Experiments for the Software Enabled Control Program Eric N. Johnson * , Daniel P. Schrage † , and George Vachtsevanos ‡ Georgia Institute of Technology {Eric.Johnson, Daniel.Schrage}@ae.gatech.edu, George.Vachtsevanos@ece.gatech.edu On August 25, 2004, a series of final experiments were flown at the McKenna urban operations complex at Ft. Benning, GA. These experiments represented the culmination of the rotary wing segment of the DARPA Software Enabled Control program. To support these efforts, an open system Unmanned Aerial Vehicle testbed architecture was developed for the GTMax and GTSpy research aircraft. This paper includes a description of these systems, and then discusses results from the final experiments. This includes: fault-tolerant flight control, adaptive flight control, fault detection and accommodation, reconfigurable control, trajectory generation, envelope protection, vision-aided inertial navigation, vision-based obstacle avoidance, and the first air-launching of a hovering aircraft. ∗†. INTRODUCTION On August 25, 2004, a series of final experiments were flown at the McKenna urban operations complex at Ft. Benning, GA. These experiments represented the culmination of the rotary wing segment of the DARPA Software Enabled Control (SEC) program. The objectives of the SEC program include control systems for Unmanned Aerial Vehicles (UAV), automation for extreme maneuvers, improved disturbance rejection and fault tolerance, and to provide reusable middleware for coordinated, embedded software control on multiple aircraft types. The rotary wing segment included team members from the Georgia Institute of Technology, Draper Laboratory, Scientific Systems Company, Inc. (SSCI), Vanderbilt University, Honeywell, the Oregon Graduate Institute, and Boeing. The technologies included in these final experiments and discussed here include neural network adaptive control, adaptive mode transitioning control, fault tolerant control, aggressive maneuver guidance logic, envelope protection, vision- aided inertial navigation, verification & validation ∗ Lockheed Martin Assistant Professor of Avionics Integration, Daniel Guggenheim School of Aerospace Engineering † Professor, Daniel Guggenheim School of Aerospace Engineering ‡ Professor, School of Electrical and Computer Engineering .Presented at the American Helicopter Society 61st Annual Forum, Grapevine, TX, June 1-3, 2005. Copyright © 2005 by the American Helicopter Society International, Inc. All rights reserved. approaches, and the Open Control Platform (OCP) reusable middleware. This paper begins with a description of the two research unmanned rotorcraft that were utilized for the SEC rotary wing final experiments: the GTMax, a small helicopter, and the GTSpy, a micro ducted-fan rotorcraft. Flight test results from the SEC final experiments follow. Figure 1 – GTMax Research UAV, primary SEC rotary-wing final experiment platform, 157 pounds, 10.2 ft diameter rotor GTMax Research Helicopter The GTMax, shown in Figure 1, is a helicopter- based UAV platform (based on the Yamaha RMAX with a 10.2 ft diameter rotor). The hardware components that make up the basic flight avionics include general purpose processing capabilities and sensing, and add approximately 35 lbs to the basic airframe for a total weight of 157 pounds as configured.