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By Tim Stoddard
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John Baillieul, Christos Cassandras, and Yannis Paschalidis (seated, from left) of ENG’s Center for Information Systems Engineering are developing sensor network control systems with far-reaching applications in manufacturing, homeland security, and space exploration. Their interdisciplinary team includes University of Massachusetts, Amherst, faculty Abhi Deshmukh, Weibo Gong (standing, from left), and Robert Gao (seated, far right). Photo by Fred Sway |
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When an unbalanced washing machine starts dancing across the floor,
a sensor inside detects the wild gyrations and halts the spin cycle.
In the future, says Christos Cassandras, washing machines and other household
appliances will go a step further: they’ll call a repairman before
a part breaks.
Cassandras, an ENG professor of manufacturing engineering,
says that appliances will be only one of many applications for so-called
sensor
networks, which feature a constellation of miniature devices that monitor
a wide range of things, from vibrations to temperature to toxic chemicals
and biological weapons. Cheap, lightweight, and built with tiny radios,
the sensors will talk to one another, coordinating
their reconnaissance and relaying their findings to a distant computer.
An aging washing machine, for example, might notify the manufacturer
of an imminent problem over a wireless Internet connection. The owner
might then receive an e-mail from the dealer to schedule a service visit
for a part that may not break for several weeks.
Sensor networks promise
to improve everything from manufacturing to homeland security to endangered
species management. But while the technology for
building tiny, cheap, and intelligent sensors is rapidly emerging, Cassandras
says, the challenge now is to develop theories for managing the flow
of information among hundreds or even thousands of networked sensors.
With an interdisciplinary team of engineers at ENG’s Center for
Information Systems Engineering (CISE), Cassandras and his colleagues
have received a prestigious award from the National Science Foundation’s
Division of Design, Manufacturing, and Industrial Innovation to develop
methods
of managing complex sensor networks.
With the award’s $2.5 million
over the next five years, the BU team will work with colleagues at the
University of Massachusetts, Amherst,
to design sensors that communicate with one another, learn on the job,
and tolerate extreme environments. The team includes Yannis Paschalidis,
an ENG associate professor of manufacturing engineering, David Castañon,
an ENG professor of electrical and computer engineering, and John Baillieul,
an ENG professor and chair of the department of aerospace and mechanical
engineering.
Initially, the CISE team will go to the chalkboard, hashing
out the theories and principles underlying sensor networks. “We’ll
be conceptualizing these new technologies and abstracting them to pictures,
equations, and
computer-based simulations,” Cassandras says. “One of our
main tasks is to develop algorithms — systematic and methodical
ways of doing something more efficiently — to make good decisions
and get this information and technology to people who can implement it.”
Down
the road, members of the team will also develop a test bed at BU to experiment
with sensor network designs. To start, however, the UMass
faculty will be principally involved in building and testing sensor hardware.
Researchers there have been designing ball bearings with tiny sensors
that monitor vibrations and send a wireless signal when the ball bearing
is breaking down and needs to be changed.
Repair thyself
The CISE team believes sensor networks
will play an important role in large-scale industrial settings. In factories,
for instance, sensors
will be embedded in tools and machines to identify problems before
they cause catastrophic failures. A variety of sensors could be used
to keep track of fuel and raw materials at every step of production,
says Paschalidis, providing a real-time inventory that would dramatically
improve planning and supply chain management. The smart washing machine
is an example of the potential for postmanufacturing product monitoring. “What
we’re headed for is a day in which products essentially will
repair themselves,” Baillieul says, “or communicate with
the factory about what’s gone wrong and what needs to be done.”
Locating
personnel and mobile equipment such as forklifts within an industrial
campus can be a major bottleneck to efficiency and safety, Cassandras
says. By tagging these mobile elements with radio frequency identification
tags (RFIDs), similar to the EZ-pass units used on the Massachusetts
Turnpike, companies would have a real-time map of the location of each
item. RFIDs are also expected to have a major impact in retail. Instead
of bar codes, items in the supermarket and department stores will have
tiny RFIDs that identify themselves to sensors on the shelves, giving
companies valuable real-time inventories.
The major challenge for the
CISE team will be integrating different kinds of information from sensors
that are built to monitor different things. “Computers
talk to each over the Internet,” Cassandras says. “That’s
fascinating, but relatively simple. What we’re dealing with in
sensor networks are heterogeneous devices that are taking qualitatively
different measurements at different rates. It’s not just the exchange
of information. There’s also the element of motion in the different
sensors, and the fact that they are essentially speaking different languages.”
As
the CISE team wrestles with the management of sensor networks, it is
prepared to adapt to the rapidly evolving sensor technologies that
will undoubtedly develop in the coming years. “As a group, we’ve
done a lot of work in other areas that are cutting edge,” says
Cassandras. “But this is really one situation where we don’t
know what’s going to happen in fundamental technology three years
down the line.”
For more information on CISE, visit www.bu.edu/systems or call 617-358-1295.
31 October
2003
Boston University
Office of University Relations