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Summary

  • Technical Group Lead of Advanced Control and Evolvable Systems Group in the Intelligent System Division at NASA Ames Research Center
  • Senior research scientist with 31 years of aerospace engineering experience
  • PhD, MS, and BS degrees in mechanical engineering, and BS degree in mathematics
  • 194 publications and text book "Model-Reference Adaptive Control - a Primer" in print
  • Research experience includes advanced control theory (adaptive, optimal, distributed-parameter systems), flight dynamics and control, flow control, aeroelasticity, structural dynamics, aerodynamics, and aircraft performance
  • Four U.S. patents and two patents in pending
  • Chair of AIAA Intelligent Systems Technical Committee (2015-2017)
  • Adjunct professor with mechanical engineering department at Santa Clara University (2006-present) teaching graduate courses in Adaptive Control, Aircraft Flight Dynamics and Performance, Aeroelasticity, and Advanced Dynamics
  • Consultant for intellectual property law office (2000-2005)
  • AIAA associate fellow

U.S. Patents

  • Four U.S. patents as first inventor, two patents in pending, and 15 NASA invention disclosures:
    • "Aeroelastic Wing Shaping Using Distributed Propulsion"
    • "Control Systems with Normalized and Covariance Adaptation by Optimal Control Modification"
    • "Variable Camber Continuous Aerodynamic Control Surfaces and Methods for Active Wing Shaping Control"
    • "Blading System and Method for Controlling Structural Vibrations"
    • "Variable Camber Continuous Aerodynamic Control Surfaces and Methods for Active Wing Shaping Control" continuation patent in pending
    • "A Real-Time Drag Optimization Control Method for Adaptive Reconfiguration of Flexible Wing Aircraft with Distributed Flight Control Surfaces" in pending

Honors and Awards

  • 54 NASA career awards including:
    • NASA Exceptional Scientific Achievement Medal
    • NASA Exceptional Achievement Medal
    • Two NASA Ames Honor Awards for Excellence in Engineer Category
    • Three NASA Patent Awards
    • Ten NASA Ames Technology Transfer Awards
    • Six NASA Group Achievement Medal
    • NASA Ames Outstanding Achievement
  • External awards:
    • AIAA Intelligent Systems Technical Committee Distinguished Service Award
    • AIAA Distinguished Service Award as Chair of Intelligent Systems Technical Committee
    • Santa Clara University Adjunct Lecturer of the Year Award
    • Best Paper Award AIAA Infotech@Aerospace Conference
    • Top-Ten-Best-Paper Award AIAA Guidance, Navigation, and Control Conference

Technical Leadership

  • Technical Group Lead of Advanced Control and Evolvable Systems (ACES) group in the Intelligent Systems Division (current) - Direct and provide technical leadership to a 21-person research group with 13 PhD and 8 MS researchers. The ACES group capabilities include:
    • Research and development of advanced flight control, guidance, and trajectory optimization
    • Research areas of damaged aircraft resilient flight control, stall recovery guidance, adaptive aeroelastic wing shaping control for transport aircraft, UAS autonomy, NASA LADEE (Lunar Atmosphere Dust and Environment Explorer) spacecraft GNC, and adaptable deployable EDL (Entry Descent and Landing) system guidance, and flow control
    • Aerospace vehicle multidisciplinary aerodynamic-aeroelasticity-flight dynamic modeling and simulations
    • Flight simulations and experiments in NASA Ames Advanced Concepts Flight Simulator, Vertical Motion Simulator, Advanced Control Technologies (ACT) laboratory, Experimental Aerial Vehicle (EAV) laboratory, SPHERES (Synchronized Position Hold, Engage, Reorient, Experimental Satellites) laboratory for NASA ISS (International Space Station), and flight test collaboration with NASA Armstrong
  • Research Lead of Performance Adaptive Aeroelastic Wing Research (current) - Lead a team of 16 researchers with a $2.5 million research budget to conduct multidisciplinary design analysis and optimization research in adaptive aeroelastic wing shaping control for flexible wing transport aircraft under the NASA Advanced Air Transport Technology Project
  • Project Scientist of NASA Integrated Resilient Aircraft Control (IRAC) Project (2007-2010) - Served as NASA ARMD (Aeronautics Research Mission Directorate) Project Scientist for IRAC Project responsible for establishing research portfolios at NASA Ames, Armstrong, Glenn, and Langley:
    • Provided technical leadership for IRAC project to conduct multidisciplinary aviation safety research with $21 million annual budget and 90 NASA employees and contractors
    • Established partnerships in advancing adaptive flight control and vehicle modeling for aviation safety with 24 funded projects at universities and companies competitively selected via NASA Research Announcement (NRA) opportunities
  • Deputy Principal Investigator of NASA IRAC Project (2005-2006) - Served as Deputy Principal Investigator for IRAC Project responsible for developing resilient flight control and modeling research portfolio, and led the research planning at NASA Headquarters to develop technical plan for the integrated airframe modeling and simulations research area
  • Associate Technical Lead of NASA Fixed Wing Project (2012-2014) - Served as Associate Technical Lead for the Aerodynamic Efficiency sub-project under the NASA Fixed Wing Project to develop research portfolio in multidisciplinary technical capabilities to advanced adaptive wing technology for transport aircraft and establish research collaboration with aircraft industry via NRA opportunities
  • Subject Matter Expert (SME) in GNC at NASA Ames (2012-2013) - Selected by Director of NASA Ames Aeronautics Directorate as SME in GNC to represent NASA Ames in the planning of NASA Fundamental Aeronautics Program and NASA Aeronautics Research Institute (NARI)
  • Project Lead of Damage Adaptive Control System (DACS) Project (2004-2006) - Led research activities at NASA Ames to conduct multidisciplinary research in collaboration with NASA Langley to develop flight dynamic modeling of damaged aircraft and adaptive flight control for damaged aircraft recovery
  • Integrated Systems Test Manager of NFAC (National Full-Scale Aerodynamic Complex) Fan Drive Project (1997-1999) - Led a 10-person engineering team to conduct structural dynamic and aerodynamic measurements and engineering analysis to assess structural integrity of the NFAC 40-By-80-By120-Foot Wind Tunnel fan drive system

Research Contributions

  • Develop innovative aircraft flight control concepts:
    • Adaptive aeroelastic wing shaping control concept for flexible aircraft and the Variable Camber Continuous Trailing Edge Flap (VCCTEF) system for aircraft drag reduction in 2010 - This multidisciplinary research led to on-going collaboration with Boeing from 2010 to present to mature performance adaptive aeroelastic wing technology for future transport aircraft. Wind tunnel experiments and CFD validation have confirmed the potential drag reduction of as much as 6%.
    • Aeroelastic wing shaping control using distributed propulsion for flexible wing aircraft in 2013 - This multidisciplinary research identifies a 2% potential fuel savings by aeroelastically tailoring thrust distribution along the wings to shape the lift distribution.
  • Lead and conduct research in the areas of aeroelasticity, aeroservoelasticity, coupled aeroservoelasticity-flight dynamics, and coupled aero-structural optimization of flexible wing transport aircraft:
    • Nonlinear aeroelasticity, aero-propulsive-elasticity, aeroservoelasticity, flutter analysis, and finite-element analysis
    • Integrated nonlinear aeroservoelasticity-flight dynamics of flexible aircraft with gust model and servo-actuator dynamics for NASA Generic Transport Model (GTM) and Boeing Truss-Braced Wing (TBW) aircraft
    • Coupled aerodynamics-structural analysis for optimization of the VCCTEF for drag reduction and maneuver load alleviation
    • Damaged aircraft flight dynamics
  • Develop advanced control technologies for flexible aircraft:
    • Adaptive Linear Quadratic Gaussian flutter suppression control
    • Distributed-parameter flutter suppression control using Lyapunov method and differential-operator optimal control method in Hilbert space
    • Adaptive real-time drag optimization control using recursive least-squares model identification method
    • Multi-objective flight control method for simultaneous control of pilot command tracking, aeroelastic mode suppression, load alleviation, and drag minimization using distributed multi-functional flight control surfaces, e.g., VCCTEF
  • Develop advanced adaptive control technologies:
    • Optimal Control Modification (OCM) method by merging optimal control theory with adaptive control theory
    • Bi-objective and multi-objective OCM
    • Performance optimizing multi-objective adaptive control with time-varying reference model
    • Least-squares model-reference adaptive control with Chebyshev orthogonal polynomial
    • Singular perturbation adaptive control for plants with slow actuator dynamics
    • Bounded Linear Stability Analysis (BLSA) and metric-driven adaptive control
    • Hybrid direct-indirect nonlinear dynamic inversion adaptive control
  • Conduct adaptive flight control experiments on NASA high-fidelity flight simulator and full-scale research aircraft:
    • Normalized OCM flight experiment on NASA F-18 research aircraft, tail number 853, at NASA Armstrong in 2010 and 2011
    • Normalized neural network intelligent flight control system flight experiment on NASA F-15 research aircraft, tail number 837, at NASA Armstrong in 2006
    • Pilot handling qualities evaluation of OCM, BLSA metric-driven adaptive control, and hybrid adaptive control in NASA Ames Advanced Concepts Flight Simulator in 2009
  • Develop flow control methods:
    • Distributed-parameter optimal control of hyperbolic conservation laws based on Euler equations for flow separation control by stator air injection in gas turbine engines
    • Distributed-parameter model predictive optimal control of Mach number regulation in NASA Ames transonic wind tunnel using hyperbolic conservation laws based on Euler equations
  • Lead and conduct trajectory analysis and optimization:
    • Minimum-time trajectory optimization of aircraft flight path in wind field
    • Minimum-fuel trajectory optimization based on optimal control and genetic algorithm
    • Range analysis for optimal cruise trajectory
  • Lead and conduct analytical and experimental structural dynamics of rotor blades:
    • Development of finite-element structural dynamic code for frequency and forced response analyses of rotary wings
    • Modal analysis testing of NASA Ames 11-Foot-By-11-Foot Transonic Wind Tunnel (TWT) compressor rotor blades and NFAC (National Full-Scale Aerodynamic Complex) 40-Foot-By-80-Foot-By-120-Foot Wind Tunnel fan blades
    • Instrumentation, vibration measurements, and structural dynamic analyses of 11-Foot-By-11-Foot TWT compressor rotor blades and NFAC fan blades
  • Lead and conduct aerodynamic analysis and experimental aerodynamics:
    • Development of unsteady mean flow CFD code for modeling 11-Foot-By-11-Foot TWT using a mixed implicit-explicit wave-splitting scheme solution method in non-conservation form
    • Turbomachinery aerodynamic analysis and design optimization of NASA Ames 12-Foot Pressurized Wind Tunnel (PWT) and 11-Foot-By-11-Foot TWT compressor
    • Aerodynamic measurements and analyses of flow characterization of 12-Foot PWT and 11-Foot-By-11-Foot TWT

Publications

  • More than 190 publications in many engineering disciplines including adaptive control, optimal control, distributed parameter control, flow control, aeroelasticity, flight dynamics, structural dynamics, aerodynamics, computational fluid dynamics, and turbomachinery fluid dynamics:
    • Textbook Model-Reference Adaptive Control - a Primer, ISBN 978-3-319-56393-0, Springer-Verlag, 2017
    • 27 journal articles and 3 in pending
    • 156 conference papers
    • 5 NASA reports
    • 4 book chapters
    • Co-editor of 100-page AIAA document “Roadmap for Intelligent Systems in Aerospace”
  • Work on flexible wing aircraft drag reduction control appears on the aerospace industry magazine Aviation Week & Space Technology in January 2013 and February 2012.

Keynote and Invited Speaker and Seminars

  • Invited Talks:
    • Invited keynote speaker by the German Aerospace Center DLR at the inauguration of the Robotics and Mechatronics Center in Oberpfaffenhofen, Germany in 2016 on "Progress in NASA Flight Control Research for Improved Safety and Performance of Next-Generation Aircraft"
    • Invited speaker by the Boeing Company at the Aircraft Multidisciplinary Design Analysis and Optimization (MDAO) Workshop in Seattle, WA in 2016 on "MDAO and Control of Performance Adaptive Aeroelastic Wing"
    • Invited speaker at NASA Engineering Safety Center GNC Committee Meeting at NASA Ames in 2017 on “Flight Control of Flexible Aircraft”
    • Invited speaker by Yale University at the Eighteenth Yale Workshop on Adaptive and Learning Systems in 2017 on “Peformance Optimizing Adaptive Control with Time-Varying Reference Model Modification"
    • Invited panelist by MIT at the AIAA Robust Tactical Planning and Mixed Initiative Control for Aircraft Initiative Control for Aircraft (and Spacecraft) Workshop in Arlington, VA in 2005 on “Tactical Planning and Intelligent Control of Degraded Flight Performance”
  • Technical Seminars
    • Seminar at TU Delft in the Netherlands in 2016 "Progress in NASA Flight Control Research for Improved Safety and Performance of Next-Generation Aircraft"
    • NASA Aerospace Modeling and Simulations Seminar in "A Framework for Adaptive Aeroelastic Wing Shaping Control"
    • Carnegie-Mellon University Seminar in 2012 "NASA Adaptive Control Research - Progress and Challenges"
    • NASA Aeronautics Technical Seminar in 2010 "NASA Adaptive Control Research - Progress and Challenges"
    • Santa Clara University Seminar in 2009 on eminar "Adaptive Control Research - Progress and Challenges for NASA Aviation Safety Program"

Professional Activities

  • Chair of the AIAA Intelligent Systems Technical Committee in 2015-2017 which comprises 50 professional members from the government, industry, and academia
  • General chair of the AIAA Infotech@Aerospace Conference in 2012
  • Chair of the AIAA Intelligent Systems Workshop in 2015
  • Member of AIAA Nomination Board for AIAA President and Board of Technical Directors Election in 2016
  • AIAA associate fellow
  • Adjunct professor at Santa Clara University in mechanical engineering department since 2006 teaching graduate courses:
    • Two-course series in adaptive control
    • Two-course series in aircraft flight performance and dynamics
    • Three-course series in advanced dynamics
    • Special topic in aeroelasticity
  • Consultant for intellectual property law office in San Jose, CA in 2000-2005 on 33 patent cases
  • Member of 5 PhD thesis committees at Georgia Tech (Prof. Anthony Calise), UC Davis (Prof. Ron Hess), UC Santa Cruz, Carnegie-Mellon University, and University of South Florida; and 3 MS thesis committees at Technical University Delft in the Netherlands and Oklahoma State University
  • Journal reviewer:
    • Control journals: IEEE Transaction on Automatic Control, IEEE Transactions on Control Systems Technology, IEEE Transactions on Aerospace and Electronic Systems, Elsevier Journal of Systems and Control Letters, International Journal of Robust and Nonlinear Control, Automatica, Journal of the Franklin Institute, IET Control Theory & Applications, AIAA Journal of Guidance, Control, and Dynamics, AIAA Journal of Aerospace Information Systems
    • Aerospace engineering journals: AIAA Journal of Aircraft, AIAA Journal, Elsevier Journal of Aerospace Engineering, Elsevier Aerospace Science and Technology, Acta Astronautica, Aircraft Engineering and Aerospace Technology, Chinese Journal of Aeronautics, Aeronautical Journal


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