Abstract：

Residency time constraints and activity time variation make the optimal scheduling and real-time control problem for cluster tools in wafer fabrication very challenging. This talks starts with the related cluster tool scheduling problems and their solution methodologies. It then presents a Petri net-based modeling method to address their optimal scheduling and real-time control issues. The developed Petri net models can well describe the clusters. They belong to finite-capacity, colored and timed models. It is with their help that we can easily find the needed optimal steady-state schedule and enable us to operate in real-time the cluster tools to satisfy wafer residency time constraints and overcome certain consequence due to activity time variations. A two-level operational architecture is proposed, which includes an off-line periodic scheduler and real-time controller. By this approach, the system can adapt to certain activity time variations. A cluster tool derived as a not-always-schedulable system by the existing methods is shown always-schedulable by using the proposed innovative approach. The extension of Petri net models to scheduling and control of complex hybrid systems such as oil refinery will be briefly discussed.

Biography：

MengChu Zhou (received his B.S. degree from Nanjing University of Science and Technology, Nanjing, China in 1983, M.S. degree from Beijing Institute of Technology, Beijing, China in 1986, and Ph. D. degree in Computer and Systems Engineering from Rensselaer Polytechnic Institute, Troy, NY in 1990.  He joined New Jersey Institute of Technology (NJIT), Newark, NJ in 1990, and is currently a Professor of Electrical and Computer Engineering and the Director of Discrete-Event Systems Laboratory.  His research interests are in Petri nets, computer-integrated systems, wireless ad hoc and sensor networks, semiconductor manufacturing, hybrid systems, and embedded control.  He has over 300 publications including 6 books, 130+ journal papers, and 17 book-chapters.  He co-authored with F. DiCesare Petri Net Synthesis for Discrete Event Control of Manufacturing Systems, Kluwer Academic, Boston, MA, 1993, edited Petri Nets in Flexible and Agile Automation, Kluwer Academic, 1995, co-authored with K. Venkatesh Modeling, Simulation, and Control of Flexible Manufacturing Systems: A Petri Net Approach, World Scientific, 1998, co-edited with M. P. Fanti, Deadlock Resolution in Computer-Integrated Systems, Marcel Dekker, 2005, and co-authored with B. Hruz, Modeling and Control of Discrete Event Dynamic Systems, Springer, 2007. Dr. Zhou served as Associate Editor of IEEE Transactions on Robotics and Automation from 1997 to 2000, and IEEE Transactions on Automation Science and Engineering from 2004-2007, and currently Managing Editor of IEEE Transactions on Systems, Man and Cybernetics: Part C, Editor of IEEE Transactions on Automation Science and Engineering, Associate Editor of IEEE Transactions on Systems, Man and Cybernetics: Part A and IEEE Transactions on Industrial Informatics, and Editor-in-Chief of International Journal of Intelligent Control and Systems.  He was General Chair of 2008 IEEE Conf. on Automation Science and Engineering, General Co-Chair of 2003 IEEE International Conference on System, Man and Cybernetics (SMC), Founding General Co-Chair of 2004 IEEE Int. Conf. on Networking, Sensing and Control, and General Chair of 2006 IEEE Int. Conf. on Networking, Sensing and Control.  He was the recipient of NSF’s Research Initiation Award, CIM University-LEAD Award by Society of Manufacturing Engineers, Perlis Research Award by NJIT, Humboldt Research Award for US Senior Scientists, and Outstanding Contribution Award of IEEE SMC Society. He is a Fellow of IEEE. He has been a Visiting Chang Jiang Scholar (funded by PRC Ministry of Education) at XiDian University since 2007.