A Matrix Framework for Discrete Event Control of Flexible Manufacturing Systems

Date: 18 Oct 2004 - 18 Oct 2004

Venue: SIMTech, Auditorium, Tower Block, Level 3


To remain competitive in a global economy, companies have refrained from using the obsolete fixed flow manufacturing systems and are now adopting the newly invented Flexible Manufacturing Systems (FMS). A patent has been granted for this novel device.

The usefulness of FMS lies in its capacity to rely on the same machines and robots that produce different products, depending on the sequence of jobs performed. The emergence of additional factors including the requirements for fast reprogramming of FMS, dynamic job sequencing, and conflict resolution for shared resources have placed increased demands on the FMS supervisory controller. Any machine-generated plan can be represented in terms of four matrices - two for job sequencing and two for resource assignment. Given these four Task Plan Matrices, it is straightforward to configure a rule-based DE controller that can sequence the jobs and assign shared resources dynamically in real-time.

The job sequencing matrices contain information that resembles the Bill of Materials and assembly tree. The second pair of matrices contains information that resembles the resource requirements matrix. Rigorous matrix techniques are given for analysing the circular wait structure of the FMS.
In terms of certain associated 'critical siphons', such techniques are given for shared resource dispatching guaranteed to eliminate deadlock. This MAXWIP technique amounting to a generalised sort of feedback control that offers the best performance possible will be discussed.

This seminar will focus on the mechanism of the Flexible Manufacturing Systems (FMS) and its industrial applicability. Participants will learn about the new matrix framework for the design and analysis of discrete event supervisory controllers developed at the University of Texas at Arlington.

About the Speaker

Dr Frank L Lewis received his Master of Electrical Engineering, Master of Science in Aeronautical Engineering and PhD from Rice University, University of West Florida and Georgia Institute of Technology in 1971, 1977 and 1981 respectively. He holds the appointment as Professor at the University of Texas at Arlington.

Dr Lewis is the recipient of NSF (National Science Foundation) Research Initiation Grant and has been continuously funded by NSF since 1982. He has also received US$4.8 million in funding from NSF and other government agencies including significant DoD (Department of Defence) SBIR (Small Business Innovation Research) and industry funding since 1991.

His current research interests include intelligent control, neural and fuzzy systems, microelectromechanical systems (MEMS), wireless sensor networks, nonlinear systems, robotics, condition-based maintenance, and manufacturing process control.

Dr Lewis holds 3 US patents and is the author, co-author of 157 journal papers, 23 chapters and encyclopedia articles, 239 referred conference papers and nine books. He won several distinguished awards including the Fulbright Research Award, the American Society of Engineering Education F.E. Terman Award, three Sigma Xi Research Awards, the UTA Halliburton Engineering Research Award, the UTA University-Wide Distinguished Research Award, the ARRI (The Automation and Robotics Research Institute) Patent Award, etc. He is a Charter Member of the UTA Academy of Distinguished Scholars, a Fellow of the IEEE, a member of the New York Academy of Sciences, and a registered Professional Engineer in the State of Texas.

Who Should Attend
Automation, Control Engineers and Logistics Managers, Researchers responsible for controls / robotics / automation / mechatronics as well as academic staff and students.
This is a non-chargeable seminar, co-organised by Singapore Institute of Manufacturing Technology and IEEE Control Chapter.

Registration is on first-come-first-served basis.

To register, please email your name, company name and email address to