Robust Adaptive Control for Input Constrained Systems: Theory and Applications

We present adaptive controllers with anti-windup augmentation to handle one of the most common memoryless nonlinearities in physical systems, namely the input saturation. The proposed anti-windup compensators can be either Linear Matrix Inequality (LMI) or Riccati-based, and the overall indirect scheme can be systematically extended to address systems with significant input magnitude and rate constraints. The control structure including the anti-windup compensator is combined with an adaptive law using the Certainty Equivalence Principle, and the stable performance of the nominal design is guaranteed to be preserved in the presence of input nonlinearities despite the unknown plant parameters. Our robust adaptive control design methodology can be employed to recover the unconstrained tracking performance of plants with large parametric uncertainties by suppressing the adverse saturation effects. In order to demonstrate the controller performance a range of application results will be presented including Unmanned Aerial Vehicles (UAVs) in optimal flight with significant elevator deflection constraints and thermal effects, cargo ship maneuvers with modeling uncertainties, limited rudder angle, wind and wave disturbances, and the control of uncertain vehicle yaw dynamics subject to steering angle limitations and crosswind effects. The efficiency of the proposed adaptive steering controller will be further investigated through simulation results for several control efficiency loss scenarios in the presence of additional steering angle rate constraints.

Nazli E. Kahveci received the B.S. degree in Electrical and Electronics Engineering from the Middle East Technical University (METU), Ankara, Turkey in 2002, and the M.S. and Ph.D. degrees in Electrical Engineering from the University of Southern California (USC), Los Angeles in 2004 and 2007, respectively. She was a Research Assistant with the Center for Advanced Transportation Technologies from 2002 to 2007, and joined Ford Motor Company, Dearborn, MI in 2008. She had summer internship experiences in flight controls with NASA Dryden Flight Research Center, Edwards, CA in 2004 and the Boeing Company, Everett, WA in 2006. Her research interests include robust adaptive control design techniques, vehicle routing with time windows, flight path optimization for unmanned aerial vehicles, and automotive powertrain controls. Dr. Kahveci was the recipient of the 2006 Boeing Satellite Systems Platinum Scholarship, the 2007 Certificate of Merit Recognition granted by the USC Women in Science and Engineering, and the 2007-2008 Academic Year Special Award presented by the USC Graduate School and the Center for Excellence in Teaching. She has served as a Program Committee Member and Associate Editor for the IEEE Intelligent Vehicles Symposiums since 2007, and as an invited panelist and reviewer for the National Science Foundation since 2008.