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ENG shares $5 million grant to develop communicating networked control systems

By Brian Fitzgerald

Imagine a device that keeps an inventory of the contents of your refrigerator. Getting low on orange juice? Lettuce wilting? No problem. "Your refrigerator will talk to your personal computer, and will run software that will keep an inventory of the food inside it," says John Baillieul. "For instance, it will know by reading bar codes how old your milk is. It will also make your grocery list for you."

	John Baillieul. Photo by Kalman Zabarsky

Is such a device necessary? Baillieul, professor and chairman of the ENG department of aerospace and mechanical engineering, knows that humankind hasn't yet reached The Jetsons stage of automation, but he uses the refrigerator model to demonstrate how interoperable networks of "smart devices" could be used.

"Potential application for smart device networks range from those that are borderline frivolous to those that will enable important new technologies," says Baillieul. "We have tried to focus our research on some of the more serious applications in both the civilian and military context. In cars, for instance, automakers will be able to install communicating networked control systems -- instead of wires -- for every function, from power windows to brakes."

The U.S. Department of Defense has so much faith in this research that it recently awarded BU and three other universities a shared $5 million Multidisciplinary University Research Initiative grant to integrate control and communications technologies. BU is the prime recipient of the grant. The other universities involved in the collaboration are Harvard University, the University of Illinois, and the University of Maryland.

Baillieul says that the explosive growth in the use of wireless communications over the last decade -- think of the ubiquity of the cellular phone -- has been fueled mainly by the availability of smaller and lower cost digital electronics that use new and sophisticated algorithms for coding, modulation, and power control. "At the same time, there has been a less visible, but still dramatic, growth in the use of microprocessors in the control of a wide variety of devices," he says. "But there still hasn't been a strong merging of these two technologies."

The time is right, he says, to develop the mathematical foundations on which scientists can build the tools necessary to achieve better integration of control and communications technologies. The U.S. Army, for example, wants to improve the performance of its units in armed conflict. How invaluable would it be to have a networked integration of webs of battlefield sensors? Picture a robot with night vision relaying what it sees to an unmanned aerial vehicle, and at the same time feeding the information to a tactical operations center, which can then instantaneously provide target location data to artillery batteries. "In urban warfare, you want to send out sentinels to detect enemy activity," says Baillieul. "But suppose chemical agents are being used. In these types of situations, the military is eager to see the maximum extent that humans can be taken out of the loop."

The research team, which includes Ioannis Paschalidis, an ENG associate professor of manufacturing engineering, and Professor Thomas Bifano, chairman of the ENG manufacturing engineering department, will devote special attention to improving the Department of Defense's Joint Tactical Information Display System and the Air Force's Fighter Data Link technologies. But they will also aim their work beyond purely military applications, says Baillieul, because there will be an increasing public demand for devices that can communicate with one another.

At present, companies are developing highly localized wireless networks based on technologies such as Bluetooth. "Bluetooth is a hardware and communications protocol specification that is being developed by Nokia, Intel, IBM, Erikson, and Motorola," says Baillieul. "This is a hardware specification that will provide very small integrated circuits that have a low-power 2.5 gigahertz radio transmitter-receiver on them. We have several in our lab. This technology will give a wide variety of smart devices the kind of communication capability that cell phones have now. When a device is brought into a room where there is Bluetooth technology, it will immediately start to talk to other devices in the room, the same way your cell phone talks to base stations. It will establish itself as part of a piconet." A piconet is an ad hoc low-power radio network that is dynamically configured to interconnect sensors, actuators, and computer processors.

Important applications include the use of distributed arrays of sensors and actuators to control complex physical processes. One example, on which Baillieul and his colleagues are working, uses arrays of micro jets and microelectrical sensor systems to control airflow over aircraft wings and through the compressor stages of gas turbine engines. "The idea is that through careful coordination of the actions of very small scale devices, the inherently unstable fluid processes can be controlled to enhance performance with very small input from the actuators," says Baillieul. "This is probably the most demanding kind of application we currently envision for networked communicating control systems."

However, do we really need a device that not only notifies you when the expiration date on your milk carton has passed, but also orders another quart from the grocery store? Not really, but potential applications include remotely coordinated manufacturing (linking supply chains and coordinating distribution), and robotic surgery. Computer companies have touted such visions for years, but because of technical problems that center on reliability and cost, there has not yet been a strong melding together of communications and microprocessing technologies. "But the possibilities inherent in such a merger are so attractive that there is a compelling argument that we should devote whatever research effort it takes to solve the technical problems that stand in the way," says Baillieul.

23 April 2001
Boston University
Office of University Relations