Welcome to the

Control Of Discrete Event Systems (CODES) Laboratory…

The Control of Discrete Event Systems (CODES) Laboratory involves faculty

and graduate students from the Division of Systems Engineering and operates within the

Center for Information and Systems Engineering (CISE). Members of CODES conduct

research on modeling, design, analysis, performance evaluation, control, and optimization

of a variety of discrete event and hybrid systems – Communication and Sensor Networks,

Manufacturing, Transportation, Command/Control…

“Though this be madness, yet there is method in’t”

William Shakespeare…Hamlet

The rapid evolution of computer technology has brought

about the proliferation of new dynamic systems,

mostly “man-made” and highly complex.

Examples abound: computer networks, sensor networks

and cyber-physical systems, automated manufacturing

systems, air traffic control systems, integrated

command-control-information systems, etc.

Their complexity can be overwhelming.

One can only hope that there truly is some method to the

technological madness around us…

A bit of history…

Historically, scientists and engineers have concentrated on studying and harnessing natural phenomena

Which are well modeled by the laws of gravity, classical and nonclassical mechanics, electromagnetics,

physical chemistry, etc. In so doing, we typically deal with quantities such as the displacement, velocity,

and acceleration of particles and rigid bodies, or the pressure, temperature, and flow rates of fluids

and gases. These are continuous variables in the sense that they can take on any real value as time itself

continuously evolves. Based on this fact, a vast body of mathematical tools and techniques has been

developed to model, analyze, and control the systems around us. It is fair to say that the study of

ordinary and partial differential equations currently provides the main infrastructure for system analysis

and control.

From TIME-DRIVEN to EVENT-DRIVEN systems

In the day-to-day life of our “man-made” and increasingly computer-dependent world, we notice:

First, that many of the quantities we deal with are discrete, typically involving counting integers

(how many parts in an inventory, how many planes in a runway, how many telephone calls are active).

Second, that what drives many of the processes we use and depend on are instantaneous events

such as the pushing of a button, hitting a keyboard key, or a traffic light turning green.

In fact, much of the technology we have invented and rely on (especially where digital computers

are involved) is event-driven: communication networks, manufacturing systems, or the execution of

a computer program are common examples. Not only must these systems act as “event coordinators”,

but they are also expected to swiftly react to unpredictable events, rapidly adapt to changing conditions,

and guarantee their users satisfactory – if not optimal – performance.

In short, all activity in these systems is due to asynchronous occurrences of discrete events, some

Controlled (like hitting a keyboard key) and some not (like a spontaneous equipment failure). This

feature lends itself to the term Discrete Event System (DES). When systems combine both time-driven

and event-driven behavior, we then deal with Hybrid Systems.

Research in Discrete Event and Hybrid systems

The main challenges we face in designing and controlling discrete event and hybrid systems come from:

• Inherent complexity (combinatorial explosion in many cases)
• Unpredictability, uncertainty
• Increasingly ambitious “high-performance” technological requirements

CODES Lab activities cover a wide spectrum, from basic research to the development of software tools.

These activities include:

• Design and real-time control of communication and sensor networks, manufacturing systems and

transportation system

• Decision support systems for quality-of-service guarantees or optimal performance
• Software testing and verification
• Strategic planning: getting information to decision makers fast and in a comprehensive form
• Developing a new generation of concurrent and parallel simulation tools
• New methods for cooperative control of wirelessly networked devices
• Autonomously reconfigurable systems

For more information, visit Research Projects, Selected Publications, and various

interactive demos and video clips of CODES lab experiments involving wireless

sensor networks and robots under WWW Resources.

If you are interested in applying for admission to our graduate program and joining the CODES

Lab, Center for Information and Systems Engineering (CISE), or the Division of Systems Engineering,

Please visit Graduate Admission Information.