Iterative Learning Control for Precision

Manufacturing Applications

Professor Andrew Alleyne

University of Illinois at Urbana-Champaign

Department of Mechanical and Industrial Engineering

This talk will discuss recent developments in improving the performance of Iterative Learning Control (ILC) schemes and their applications to manufacturing applications. In particular, we will motivate the use of ILC schemes with a solid freeform fabrication (SFF) technique used for construction of micro-scale periodic structures. The particular SFF approach used deposits colloidal or polymeric material to rapidly “build up” complex 3 dimensional structures with feature sizes ranging from 1 micron to several hundred microns. We will introduce a system that focus on the creation of periodic, lattice-like structures with several potential applications. This is a truly interdisciplinary research effort involving Materials Science, Manufacturing, and Controls.

After the demonstration of several SFF processes, a brief introduction to Iterative Learning Control will be given. Subsequently, we will present two particular improvements that can be made to existing ILC approaches. The first improvement will be the use of time-varying filters within the ILC structure. We show that appropriate choices of time-varying filters can improve upon the tradeoffs inherent in linear time-invariant (LTI) filters used for stabilization and convergence. The second improvement combines the repetitive nature of the ILC framework with the cross-coupled control approach used for improving manufacturing system contouring applications. For both improvements we present stability analyses to provide algorithmic guarantees. Additionally, we demonstrate the benefits in performance with numerical and experimental results.

Brief Biography

Professor Alleyne received his B.S. in Engineering Degree from Princeton University in 1989 in Mechanical and Aerospace Engineering. He received his M.S. and Ph.D. degrees in Mechanical Engineering in 1992 and 1994, respectively, from The University of California at Berkeley. He joined the Department of Mechanical and Industrial Engineering at the University of Illinois, Urbana-Champaign in 1994 and is also appointed in the Coordinated Science Laboratory of UIUC. He currently holds the Ralph M. and Catherine V. Fisher Professorship in the College of Engineering, was awarded the ASME Dynamics Systems and Control Division’s Outstanding Young Investigator Award in 2003, and was a Fulbright Fellow to the Netherlands where he held a Visiting Professorship in Vehicle Mechatronics at TU Delft. Additionally, he is a Fellow of ASME. His research interests are a mix of theory and implementation with a broad application focus. He has been active in the ASME, the IEEE, and several other societies. Further information about the toys he and his students play with can be found at the following website: http://mr-roboto.me.uiuc.edu.

Friday, December 1, 2006

3:30 – 4:30 p.m.

Rm. 1500 EECS