Aerospace Control Research at the Ohio State University Aerospace Engineering Department Rama K. Yedavalli Professor Department of Aerospace Engineering The Ohio State University Columbus, OH Oct 11,2006

Outline  Overview of Current Research Projects  Possible Collaborative Avenues  Conclusions

Current (and Past) Research Projects Current Research Activities Chemotherapy Drug Delivery (Active,unfunded) NASA Dryden (Current) AFRL/PR (past) CCCS Flight Control (past) STTR/SBIR (trying) CCCS Flow Control (past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (Active, unfunded)

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active,unfunded) NASA Dryden (Current) AFRL/PR (past) CCCS Flight Control (past) STTR/SBIR (trying) CCCS Flow Control (past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (Active,unfunded)

CCCS: Flight Control ( ) Robustness Analysis of the X-40A Dynamic Inversion Controller Implementation of combined Dynamic Inversion - State Dependent Riccati Equation Technique Stability Domain Estimation (Region of Attraction) Method of Vector Norms Sum of Squares Programming Dynamic Inversion Control Allocation SDRE Redesign

CCCS: Flight Control  Graduate Student: Praveen Shankar –Funded by CCCS from Oct 2001 – Sept 2004  Publications: –P. Shankar, R.K. Yedavalli, D.B. Doman “Stability Domain Estimation for Dynamic Inversion Embedded SDRE Flight Controller”, Proceedings of AIAA-GNC Conference 2004, Providence, RI –P. Shankar, R.K. Yedavalli, D.B. Doman “Dynamic Inversion via State Dependent Riccati Equation Approach: Application to Hypersonic Vehicles”, Proceedings of AIAA-GNC Conference 2003, Austin, TX –R.K. Yedavalli, P. Shankar, D.B. Doman “Robustness Study of a Dynamic Inversion Based Indirect Adaptive Control System for Flight Vehicles with Uncertain Model Data”, Proceedings of IEEE ACC Conference 2003

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR (Past) CCCS Flight Control (Past) STTR/SBIR (trying) CCCS Flow Control (Past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (Active,unfunded)

CCCS: Flow Control ( )  Model Reduction for Cavity Flow Control System  Component Cost Analysis and Principal Component Analysis  Proper Orthogonal Decomposition and Galerkin projection  Nonlinear Model Reduction  Cavity Flow Control D L W M  U 

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR (Past) CCCS Flight Control (Past) STTR/SBIR (trying) CCCS Flow Control (Past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (Active,unfunded)

NASA Dryden ( )  Current Research: –Implementation of Growing Radial Basis Function Neural Network to minimize error due to modeling and failures in control surfaces –Successfully implemented for F-15 Dynamic Inversion Controller and F-18 Robust LQR Tracker –To be implemented on piloted simulation at NASA Dryden  Future Research: –Design of Adaptive Critic (Neural Network with Reinforcement Learning) for reference model adaptation during critical failure Reference Model PI Controller Neural Network Dynamic Inversion Control Allocator δ ω ω des F-15

NASA Dryden  Graduate Student: Praveen Shankar –Funded by NASA Dryden –Ph.D. defense in Spring’07 –Praveen won the prestigious AIAA Orville Wright Graduate Student Award this year

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR (Past) CCCS Flight Control (Past) STTR/SBIR (trying) CCCS Flow Control (Past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (Active,unfunded)

NASA Glenn / GEAE ( )  Development of Model-predictive Engine Control to adapt to –Engine degradation –Engine-to-engine variation –System faults  Development of Estimation techniques (Collaboration with GE) –Estimation of unmeasured parameters: Thrust and Stall Margin –Improved accuracy and robustness to system faults

NASA Glenn / GEAE ( )  Application of model based control strategies for engine control  Application of model based diagnostic techniques –Sensor fault detection and isolation in Turbine Engine simulation model using Neural Networks and bank of Kalman Filters  Application of model based prognostic techniques to Turbine Engine simulation model

NASA Glenn / GEAE ( )  Paper published in Turbo Expo ’06 in Barcelona  Another paper on Engine Fault Detection using Dynamic/Adaptive Threshold under review for Turbo Expo’07 in Montreal

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR (Past) CCCS Flight Control (Past) STTR/SBIR (trying) CCCS Flow Control (Pastt) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (Active,unfunded)

 Turbine Engine Control, Health Management, Diagnostics and Prognostics  Nonlinear transient simulation model development of Turbine Engine using Matlab/Simulink  Application of model based control strategies for engine control  Application of model based diagnostic techniques –Sensor fault detection and isolation in Turbine Engine simulation model using Neural Networks and bank of Kalman Filters  Application of model based prognostic techniques to Turbine Engine simulation model AFRL / PR /UTC ( )

 Graduate Student: Majid Siddiqi –Funded by UTC from January 2004 – June 2005 –R.K. Yedavalli, M. Siddiqi, A.Behbahani, “Model- based Prognostics of Turbine Engines for Predicting Blade Cracks”, paper to be presented at the 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR (Past) CCCS Flight Control (Past) STTR/SBIR (trying) CCCS Flow Control (Past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (Active,unfunded)

STTR  Development of hardware and software algorithms to provide autonomous flying capability for formation of manned rotorcraft vehicles  Implementation of Robust LQR tracker with artificial intelligence for pattern recognition  Use of GPS and wireless communication

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR (past) CCCS Flight Control (Past) STTR/SBIR (trying) CCCS Flow Control (Past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (Active,unfunded)

US Army ( )  Robust Stability and Control of Multi-body Ground Vehicles under Uncertainty and Failures  Ground Vehicle Dynamics –Rollover stability –Ride and Handling Performance –Stability under failures  Efforts to Collaborate with TARDEC in Warren, MI

Robust Stability and Control of Multi- body Ground Vehicles (ARO)’06-’09

 Develop a control algorithm for the steering command as a feedback of roll rate, scheduled in terms of forward velocity v and c.g height differential h.  Develop a `robust’ control law that will perform well in as wide velocity range as possible and in as wide changes in the cg height as possible.  The problem is challenging because the parameter values vary significantly as a function of the operating condition  So innovative feedback control schemes are needed to improve the performance of the vehicle in the presence of all these real life perturbations and even in component failures.

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR/UTC (past) CCCS Flight Control (past) STTR/SBIR (trying) CCCS Flow Control (past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (active,unfunded)

Chemotherapy Drug Delivery  Application of uncertain linear systems control theory with structured uncertainty to drug delivery schedule relating clinical information in cancer chemotherapy λδ γ P Cycling Cells α β Q Resting Cells time T a T/a dose

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR (past) CCCS Flight Control (past) STTR/SBIR (trying) CCCS Flow Control (past) US Army (Current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (active,unfunded)

Qualitative (Sign) Stability of Ecology (Need Sponsorship)  Application of concepts of biology and life science to engineering systems: Qualitative (sign) stability and Robust stability (ACC’06)

Qualitative (Sign) Stability of Ecology (Need Sponsorship)  Given a matrix with only +, - and 0s (no magnitudes), get necessary and sufficient conditions for Hurwitz stability using ideas from Ecology (ACC’06, ROCOND’06)  Matrices which are sign stable are Hurwitz stable for any magnitudes we put in those locations!  But the converse is not true  Using Sign Stability of Ecology, can tabulate all the 2x2, 3x3 and 4x4 matrices which are sign stable `apriori’! Extremely interesting and amazing !

New Control Design Method using Sign Stability of Ecology  Controllers designed using Sign Stability ideas are Robust and Nonfragile (under review for ACODS’07)  They produce Controllers of Reduced Dimension and Reduced Control Effort because they `work’ with the natural dynamics rather than `fight’ with it.  Examples of Control Design Using Sign Stability include Satellite Attitude Control and Formation Flying Control  Sign Stability based Controller highly superior to Pole Placement and LQR controllers

Current Research Projects Current Research Activities Chemotherapy Drug Delivery (Active) NASA Dryden (Current) AFRL/PR (past) CCCS Flight Control (Past) STTR/SBIR (trying) CCCS Flow Control (past) US Army (current) NASA Glenn / GEAE (Current) Uncertain Systems Research (Active) Qualitative Stability (active,unfunded)

Uncertain Systems Research (active)  New Technique for Robust Stability Analysis of Families of Linear State Space Systems –Application to Stability Analysis of Flight Dynamics under Uncertain Parameters –Application to Determination of Drug Delivery Schedule for Cancer Chemotherapy Models with Uncertain Pharmacokinetic parameters –Application to Multibody Ground Vehicles with Uncertain Dynamics and Failures –Applications possible in Engineering Dynamic Systems in various disciplines

Possible Collaborative Avenues  Qualitative (sign) Stability concept from Ecology and its role in Uncertain Engineering Systems –Need sponsorship of this important research  Possible continued research in Turbine Engine Fault Diagnostics and Health management –Dialogue with NASA Glenn and Engine Companies  Possible Continued Research in Stability and Robustness Guarantees for Neural Network Based Nonlinear Flight Controllers –NASA NRA under review  Will be able contribute in SBIR/STTR efforts

Conclusions  Engaged actively in varied research projects  Avenues available for collaboration  Vibrant graduate student body (Currently have 5 Ph.D students and one Masters student)  Expect continued research activity