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Air Vehicles Directorate Activities Aerospace Control and Guidance Systems Committee Lake Tahoe, NV March 1 – 3, 2006 David Doman [email protected] Control Science Center of Excellence Air Force Research Laboratory, WPAFB Control Science Center of Excellence Research Areas • Cooperative control of UAVs • Fault tolerant autonomous space access and prompt global strike • Feedback flow control Personnel • Civil servants – 11 • Military – 2 enroute • Contractor – 3 • Increase by 2/3 in summer Contributing to VA Capability Focus Areas Hingeless maneuvering Shear layer control CAV Precision GNC Long-term HSV Vision Cooperation with autonomy Reliability Safety Responsiveness Higher L/D Cooperative Operations in UrbaN TERrain (COUNTER) MAVs Critical Information to Warfighter • Provide Situational Awareness for Urban Operations – Positive Identification and Verification of Target in Cluttered Urban Environments • Is Something/Someone Important There? • Where? • What/Who? • Micro Aerial Vehicles (MAVs) – Details/Positive ID • Fly Inside City for Positive Target ID • Look Angles for Obscured Targets • Small UAVs – Big Picture • Wide Field of View but Limited View Angles • Relay and Processing of MAV Data Object Allocation Algorithm – 6.1 Research • Problem: minimize the maximum tour length for all vehicles • Constraints: • Large number of targets (20) • Real time implementation 2500 • Flyable trajectories 19 7 10 • Solution • Branch and Bound algorithm • Decouple task assignment from trajectory optimization • Traveling Salesman Problem solver • Appeal • fast feasible solution • monotonic improvement of solution • Flight Test April 06 13 2000 416 2 1500 1 1000 11 6 12 8 500 0 17 0 20 5 18 4 3 2 1 3 14 15 9 500 1000 1500 2000 6.1 research providing critical algorithms for a multi-directorate 6.2 demo program 2500 3000 Air-breathing Hypersonic Vehicle Modeling and Control • • • Problem: model and control a highly coupled airframe/propulsion system with aerothermoelastic interactions. Challenges: – Complex interactions between aerodynamics, propulsion, structures, and thermal protection system – Aerothermoelastic phenomena necessitates multidisciplinary modeling – Vehicle closed-loop response bandwidth limited Approach: – First principles modeling approach – Include thermal effects on structural dynamics – Investigate configuration modifications to improve controllability Status: – Increasing model fidelity include unsteady heat transfer for a legacy TPS – Identified canard-elevon configuration that significantly improves flight path controllability “Aerothermoelasticity” Mode Shapes Hot Freq. • Cold Temp. Canard-Elevon Interconnect Interconnect Effect on RHP Zero Fault Tolerant Responsive Space Access and Prompt Global Strike • IAG&C completed X-37 HILS testing this year at Boeing ASIL Facility – Follow-on to 2003 TIFS/X-40 AL Demo – AFRL / Barron Associates / Boeing team – 3D TAEM/AL trajectory reshaping demonstrated – Reconfigurable inner-loop control – Other flight phases: boost, post-boost and reentry to follow • Prompt Global Strike project – – – – Ablation effect modeling and simulation Adaptive PN terminal guidance with limits Severe control power limitations Tight impact requirements Aerodynamic Flow Control (OSU/CCCS) Objective: Improve robustness of aerodynamic flow control for cavity flows Technical Challenges: Order reduction of Navier-Stokes equations in a way that is amenable to control law design Controller design for highly nonlinear systems Application: Reduce aero-acoustic loading on weapons bay structures 7 8 4 5 6 Velocity m/s Progress: Developed and implemented linear quadratic control based on reduced-order models obtained using experimental data and three numerical techniques. Demonstrated advantages of closed-loop control (via simple linear controllers) over open-loop control (forcing at optimal frequency and amplitude) Control Science Collaborative Center Team: Ohio State University (lead), UD, UC, and AFIT Manpower: 7 faculty, 3 post docs, 12 grad students Established in Oct 2001 $1M per year shared equally by VA and AFOSR Cost share: $700K from State of OH, $1,055K from OSU, UC & UD Synergies and leveraging: $6M from NASA, NSF, NIST, DARPA Formal annual reviews: 100+ attendees from DoD & industry • Executive Board consists of government, industry, academia Strong Collaboration: Joint Research & Publications Invited sessions Seminars Industry visits Weekly tech discussions In-depth 6-month reviews CCCS considered a “Model Center”