세미나 및 강연

Abstract:

This seminar presents a recently discovered phenomenon that takes place in feedback systems with saturating actuators, proportional-integral control, and anti-windup. Namely, in such systems, measurement noise induces steady state error in step tracking, which is incompatible with the standard error coefficients. We quantify this phenomenon using stochastic averaging theory and show that the noise induced loss of tracking occurs only if anti-windup is present. Moreover, we show that this phenomenon takes place with any types of anti-windup known from the literature. An indicator that predicts this phenomenon is derived, and a rule-of-thumb, based on this indicator, is formulated. Illustrations with a digital printing device as well as thermal control in real-time computing systems are provided.

Speaker Bio:

Yongsoon Eun received BA in mathematics, BSE and MSE in Control and Instrumentation Engineering from Seoul National University and PhD in Electrical Engineering from the University of Michigan. He worked as a senior research scientist at Xerox Corporation Research Center in Webster, NY, USA from 2003 to 2012 before joined DGIST Information and Communication Engineering Department as an associate professor. He is currently the department chair and the director of DGIST Resilient Cyber-Physical Systems Research Center. His main research interest includes resiliency of control systems, resilient cyber-physical systems, control systems with nonlinear instrumentation, intelligent transportation systems. He is a co-author of the book “Quasilinear Control: performance analysis and Design of Feedback Systems with Nonlinear Sensors and Actuators, Cambridge University Press, 2011”, the recipient of Xerox Innovation Group Excellence in Science and Technology Award, 2011, and the DGIST achievement award in 2014.