Plenary II

Prof. Nejat Olgac

Mechanical Engineering Department,
University of Connecticut, USA

Time Delayed Systems, Bridging Between Theory and Realistic Applications

Practically motivated investigations have been conducted for over four decades in the machine tool’s regenerative chatter area bringing the time delayed dynamics into question. These efforts went on almost completely decoupled from the theoretical developments in mathematics, almost in the same chronological time span. In this presentation we wish to take a journey bridging variety of application-based research studies to the theory. Some industrial problems that await solution and corresponding theoretical developments will be revisited. Missed opportunities of cross-breeding between the two groups of researchers and potentially fertile new venues are also reviewed. Interwoven nature of knowledge creation between the practice to theory will be displayed with video clips and numerical simulations.

Several focus points in the talk are: (a) A concept of actively tuned vibration absorbers, the “Delayed Resonator”, which is inspired from machine tool chatter phenomenon, (b) Neutral class of TDS in practice, (c) Cluster Treatment of Characteristic Roots (CTCR) paradigm and its impact on single and multiple delay systems, (d) Chatter stabilization in Simultaneous Machining using “Delay Scheduling” method, (e) “Spectral Delay” and “Building Block” concepts for multiple and rationally independent delay cases, (f) Stability of multi-agent swarm control.

Biography

Nejat Olgac, Dr. Eng. Sci. Columbia Univ 1976, M.Sc. Technical Univ. of Istanbul, Turkey 1972, both in Mechanical Engineering. He managed industrial groups in Europe between 1976-81. He joined the University of Connecticut in 1981, in the Mechanical Engineering Department where he is a professor today. His research interests are in robust nonlinear controls, active vibration absorption, time-delayed systems, micromanipulation in cellular biology applications, control of autonomous swarms. Dr . Olgac holds three patents (1995-1996-1999) on the Delayed Resonator active vibration suppression technique. He is the director of Advanced Laboratory for Robotics, Automation and Manufacturing (ALARM) at UConn. Dr. Olgac was Visiting Professor at INRIA (Sophia Antipolis, France) 1988-89, SEW Eurodrive Fellow – Guest Professor at Technical Univ. of Munich, Germany in 1995-96 and Visiting Professor at Harvard University 2002-03). He was on the editorial board of the ASME Trans. of Dynamic Systems, Measurement and Control (1996-2004), and the guest editor of the Special Issue of JDSMC on Time Delayed Systems (June, 2003), is presently on the Editorial Boards of J. Vibration and Control, Int. J. of Mechatronics and Manufacturing Systems . He was a member and the Chairman of the Executive Committee of the ASME Dynamic Systems and Control Division (2001-6). Prof. Olgac is a member of the Connecticut Academy of Science and Engineering, Fellow of ASME and Senior Member of IEEE.