Adaptive control is considered to be one of the main enabling technologies that can improve both performance and safety since it can cope with uncertainties by autonomously redesigning its control input. New adaptive control architecture has been developed where a nominal controller is included in the inner-loop, with the adaptive controller in the outer-loop. The nominal controller is designed based on the known part of the system such that it can perform command tracking with the desired stability margin in the absence of uncertainties. In particular, the design is based on gain-scheduling so as to control a nonlinear plant over multiple equilibrium points. The adaptive controller is designed so as to improve the plant performance in the presence of uncertainties.

Transitioning adaptive control to flight systems requires stability to be guaranteed in the presence of input saturation which is a ubiquitous feature in control applications. An adaptive control law is proposed to compensate input saturation for a multi-input system. The overall system is shown to be semi-globally bounded with respect to the saturation limits. The adaptive system is also shown to be robust with respect to disturbances, unmodeled dynamics, time-delays, and nonlinearities, demonstrating the possibility of deriving stability margins of adaptive controllers. All theoretical findings above are validated by a 6-DoF nonlinear simulation based on a NASA X15 hypersonic aircraft.

Bio: Jinho Jang is working on his Ph.D. in the Department of Mechanical Engineering at the Massachusetts Institute of Technology Cambridge, MA. He received his Master of Science in the Department of Aeronautics and Astronautics also from MIT, and his Bachelor of Science in the School of Mechanical and Aerospace Engineering from Seoul National University Seoul, Korea.

He is currently a Research Assistant in the Department of Mechanical Engineering at MIT. He has worked on the development of adaptive flight control in the presence of uncertainties and input constraints, constructed augmented adaptive control with gain-scheduling and analyzed robustness of adaptive systems. He has also performed the simulation with high fidelity 6-DoF nonlinear aircraft models.