Air Vehicles Directorate Activities Aerospace Control and Guidance Systems Committee Lake Tahoe, NV March 1 – 3, 2006 David Doman 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 Reliability Safety Responsiveness CAV Precision GNC Long-term HSV Vision Higher L/D Hingeless maneuvering Cooperation with autonomy Shear layer control
Cooperative Operations in UrbaN TERrain (COUNTER) Provide Situational Awareness for Urban Operations –Positive Identification and Verification of Target in Cluttered Urban Environments Is Something/Someone Important There? Where? What/Who? MAVs Critical Information to Warfighter 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
Problem: minimize the maximum tour length for all vehicles Constraints: Large number of targets (20) Real time implementation Flyable trajectories 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 Object Allocation Algorithm – 6.1 Research 6.1 research providing critical algorithms for a multi-directorate 6.2 demo program
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 Temp. Mode Shapes Cold Hot Freq. Interconnect Effect on RHP Zero Canard-Elevon Interconnect “Aerothermoelasticity”
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 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)
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 Control Science Collaborative Center CCCS considered a “Model Center” Strong Collaboration: Joint Research & PublicationsIndustry visits Invited sessionsWeekly tech discussions SeminarsIn-depth 6-month reviews