June 29, 2016

Sampled-Data Models for Data Control

Abstract: Most real world systems operate in continuous time. However, control laws are invariably implemented in sampled from. This dichotomy raises the question about the connection between continuous-time and sampled-data domains. This talk will give a tutorial overview of this topic. Issues to be covered will include folding, sampled data models for linear continuous time systems and sampled data models for nonlinear continuous time systems. Particular emphasis will be placed on sampled data zero dynamics. In particular, we will show how Euler-Frobenius polynomials arise in the description of these dynamics. Recent work relating to systems having a continuous-time delay that is a fraction of the sample period will also be described.
The talk will be illustrated by a real world example arising in Power Electronics where fractional delays arise due to both practical limitations of the gate driving circuitry and timing restrictions associated with the transition between switching states, otherwise known as dead-time. The importance of accounting for delays in this context will be exemplified by showing the impact of delays on the performance of high fidelity control laws aimed at selective harmonic suppression.

Bio: Dr. Graham Goodwin received B.Sc., B.E. and Ph.D. from the University of New South Wales. In 2010 he was awarded the IEEE Control Systems Field Award and in 2013 he received the Rufus T. Oldenburger Medal from the American Society of Mechanical Engineers. He was twice awarded the International Federation of Automatic Control Best Engineering Text Book. He is a Fellow of IEEE; an Honorary Fellow of Institute of Engineers, Australia; a Fellow of the International Federation of Automatic Control, a Fellow of the Australian Academy of Science; a Fellow of the Australian Academy of Technology, Science and Engineering; a Member of the International Statistical Institute; a Fellow of the Royal Society, London and a Foreign Member of the Royal Swedish Academy of Sciences. He holds Honorary Doctorates from Lund Institute of Technology, Sweden and the Technion Israel. He is the co-author of nine books, four edited books, and several hundred papers. Graham is a Distinguished Professor at Harbin Institute of Technology (China), Northwestern University (China), Zhengzhou University (China) and Universidad Técnica Federico Santa María (Chile). He holds 16 International Patents covering rolling mill technology, telecommunications, mine planning and mineral exploration.