Control Designs for Time-Delay Nonlinear Systems with Lower-Triangular Structures and Unknown Control Directions

Abstract: A class of nonlinear systems in the lower triangular form has attracted considerable attention from researchers because many physical systems, including mechanical, electrical and bio-chemical systems, can be transformed into a lower-triangular form. System uncertainties naturally arise due to lack of knowledge of the system, or system conditions changing from internal or external factors. These uncertainties can include structural uncertainties, parametric uncertainties, time-delays and control directions. The less system information is used in the control design, the more robust the controller becomes.

This presentation discusses various control designs for nonlinear systems in the lower-triangular form and beyond that can deal with structural uncertainties, parametric uncertainties and recent developments in control designs for unknown time-delays in states and unknown control directions.

Bio: Dr. Radom Pongvuthithum received his Ph.D. from the Department of Electrical Engineering and Computer Science, Case Western Reserve University, Ohio, in 2003. From 2003–2004, he was a Research Fellow in the School of Engineering and Sciences at the University of Southampton, U.K. He joined the Department of Mechanical Engineering, Chiang Mai University, Thailand, in 2004 and currently holds the position of Professor in the same department. His research interests include nonlinear systems, adaptive control, time-varying feedback design and their applications to medical robots and energy systems.