Rejection of Unknown Narrow Band Output Disturbances using Robust Adaptive Feedback Control

Friday, October 9, 2015,  3pm,

Location: UC San Diego, Bldg EBU2, Rm 479

Prof. Petros Ioannou, USC
Friday, October 9, 2015

The suppression of unknown narrow band disturbances with time-varying characteristics has many industrial applications. The narrow band disturbances get mixed up with broadband noise of lower amplitude and usually appear at the output of the system.  The objective is to use feedback to attenuate or reject the narrow band disturbances without amplifying the broadband noise. In this talk we present   the design and analysis of an effective robust adaptive scheme that achieves the following:
·         Rejects the narrow band disturbances whose characteristics can change with time without amplifying the output noise and in the presence of plant unmodeled dynamics. 
·         It addresses the classical problem of ill-conditioning when the zeros of the plant are close to the zeros of the internal model of any of the output disturbance frequencies.
·         It addresses the problem of unknown plant model parameters and provides a complete solution in the case of minimum phase plant models.
The techniques used include an overparametrized robust adaptive filter that provides enough freedom to adaptively search for parameters that achieve both objectives namely disturbance rejection and no noise amplification. In addition it includes a feed forward filter to increase the gain of the system over the frequency range of the narrow band disturbances and therefore allow the zeros of the plant to be closer to those of the internal model of the disturbance without sacrificing performance. The problem of rejecting the unknown narrow band disturbance when the plant model parameters are unknown or change with time is solved in the case of minimum phase plant models by using a different feedback control structure that is based on adaptive pole placement control. The results are developed for SISO and MIMO LTI systems both in discrete and continuous time domain. Simulation results based on a model of a laser beam device are used to demonstrate the results.

Speaker Bio: 

Petros Ioannou received the B.Sc. degree with First Class Honors from University College, London, England, in 1978 and the M.S. and Ph.D. degrees from the University of Illinois, Urbana, Illinois, in 1980 and 1982, respectively. In 1982, Dr. Ioannou joined the Department of Electrical Engineering-Systems, University of Southern California, Los Angeles, California.  He is currently a Professor in the same Department and the Director of the Center of Advanced Transportation Technologies. He also holds a courtesy appointments with the Department of Aerospace and Mechanical Engineering and Department of Industrial Systems Engineering. He has been the Associate Director for Research for the University Transportation Center METRANS at the University of Southern California since 2006. Dr. Ioannou was the recipient of the Axelby Outstanding Paper Award by the IEEE Control System Society in 1984 and the recipient of a 1985 Presidential Young Investigator Award for his research in Adaptive Control. In 2009 he received the IEEE Intelligent Transportation Systems Society (ITSS) Outstanding ITS Application Award and the 2009 IET Heaviside Medal for Achievement in Control by the Institution of Engineering and Technology (former IEE). In 2012 he received the IEEE ITSS Outstanding ITS Research Award and in 2015 the 2016 IEEE Transportation Technologies Field Award for his work on adaptive cruise control systems to be presented at the 2016 IEEE International Conference on Intelligent Transportation Systems Conference in Brazil. Dr. Ioannou is a Fellow of IEEE, Fellow of International Federation of Automatic Control (IFAC), Fellow of the Institution of Engineering and Technology (IET), and the author/co-author of 8 books and over 300 research papers in the area of controls and applications and transportation.


Speaker Photo: 
Event Date: 
Friday, October 9, 2015