Control Seminar
Stabilization of Systems with Feedback Delay by the actandwait Control Concept
Tamas Insperger
Associate Professor
Budapest University of Technology and Economics, Budapest, Hungary 

Friday, February 10, 2012
3:30pm  4:30pm 1500 EECS


About the EventControl of systems with delay in the feedback loop is a complex task, since infinitely many poles should be controlled using only finite number of control parameters. The actandwait control is a special timeperiodic control for systems with feedback delay, where the control gains are periodically switched on and off in time. The governing equation is a delaydifferential equation with timeperiodic coefficients. The merit of the method is that if the switchoff (waiting) period is longer than the feedback delay, then the system can be transformed to a discrete map of finite dimension presenting a finite spectrum assignment problem.
Several (actually, infinitely many) periodic functions could be chosen for timeperiodic control gains. The main idea behind choosing the one that involves waiting intervals just longer than the feedback delay is that this kills the memory effect by waiting for the system’s response induced by the previous action. Although it might seem unnatural not to actuate during the wait interval at all, the actandwait concept is still a natural control logic for timedelayed systems. This is how, for example, one would adjust the shower temperature considering the delay between the controller (tap) and the sensed output (water temperature at skin).
The presentation will start with a description of the actandwait control concept for general systems with feedback delay. Then, case studies will be presented including firstorder scalar systems with feedback delay and balancing problems with reflex delay.

BiographyBiosketch: Tamás Insperger received his MSc degree in mechanical engineering in 1999 and his PhD degree in applied mechanics in 2002 form the Budapest University of Technology and Economics, Hungary where he currently holds an associate professor position. He held visiting positions at Auburn University, AL, 1997, University of Kaiserslautern, Germany, 2000, and Washington University, St. Louis, MO, 2001, and he is currently a visiting professor at Claremont Colleges, CA. His research interests are in the area of timedelay systems and digital control focusing on applications like machinetool vibrations and robotics. He is the author of approximately 100 publications including the book Semidiscretization for timeselay systems, Springer, 2011. 
Additional Information
Contact: Ann Pace
Phone: 7635022
Email: ampace@umich.edu
Event Sponsor: Bosch, Eaton, Ford, GM, Toyota, Whirlpool and the MathWorks
Open to: Public


