ADVANCES
20 Scientific American, July 2019
Illustration by Thomas FuchsENGINEERING
Electricity
Detective
A new sensor system warns when
an electrical device is about to fail
From the outside, the main diesel engines
on the U.S. Coast Guard cutter vessel Spen-
cer looked normal. But a newly de vel oped
sensor system indicated that a bank of heat
ers, used to warm up the engines before they
rumble into action, had failed. When the
crew members removed the heaters’ metal
cover, they found smoking, corroded wires.
Not only were the heaters incapacitat
ed, “their electrical insulation was starting
to fray and crack, on the verge of starting a
fire,” says Massachusetts Institute of Tech
nology professor Steven Leeb, who was
senior author of a study published in March
in IEEE Transactions on Industrial Informatics
describing the new system. “Our power
monitor was able to detect the gradual
changes over the course of a year and saw
a time when it failed severely.”
The system relies on a technology
called nonintrusive load monitoring
(NILM). In ships and buildings alike,
many devices are often connected to a sin
gle power supply, and each one creates
unique changes in the flow of current.
A NILM sensor installed at one point in
the electrical network can extract these
distinct “fingerprints” to determine how
much energy each device is using. Al
though NILM dates back to the 1980s,
practical applications have emerged only
in the past few years as utilities and inde
pendent startups began developing smart
meters to monitor energy usage in homes
and buildings.
The new system processes NILM data
and displays the information via dashboardsonboard Coast Guard cutters. “The [re
searchers have] made a usable tool,” says
David Irwin, an assistant professor of electri
cal and computer engineering at the Univer
sity of Massachusetts Amherst, who was
not involved in the study. Whereas many
academic NILM projects can be esoteric,
Irwin says, Leeb’s team has focused on real
world use, successfully adapting a sensor for
commercial applications.
A similar dashboard interface can warn
homeowners of failing appliances—and
could be critical in industrial or military
settings. “The diagnostics work is directed
toward detecting when things break—and
even better, prognosticating when they
may break,” Leeb says. Early detection of
the Spencer’ s faulty engine component
enabled the Coast Guard to replace it
while the vessel was still docked.
“Almost nobody likes having something
be broken,” he says, but on cutters—or in
refineries, chemicalprocessing operations,
manufacturing plants or commercial build
ings—one broken part can take down a
much larger system in a socalled mission
cripple, causing serious and wideranging
consequences. — Sophie BushwickFor more details, visit
http://www.ScientificAmerican.com/
jul2019/advances
IN THE NEWSQuick
Hits
By Jim DaleyK E N YA
Paleontologists have identified a fossil jawbone in
the Nairobi National Museum that came from a
previously unknown giant carnivore, which roamed
Africa 22 million years ago. The predator was likely
larger than a polar bear and had banana-sized fangs.NEPAL
Researchers confirmed the nation’s first recorded
tornado, which occurred during a devastating storm
in March. The team relied on satellite imagery and
posts on social media to make the identification.AUSTRALIA
The government announced it
will not regulate gene-editing
technology provided it does
not introduce new genetic
material to target sites in
the genome. Editing human
embryos used for reproduction
is still banned, however.ANTARCTICA
Emperor penguins have abandoned one of their biggest
breeding colonies, possibly because of sea-ice loss.
Biologists found that the population, which reached about
25,000 breeding pairs of birds in 2010, collapsed in 2016
and has not rebounded since.GUATEMALA
Archaeologists unearthed
the largest known Mayan
figurine factory. The more
than 1,000-year-old
workshop mass-produced
intricate statues that were
likely used in diplomacy
as gifts to allies.
CHINA
The Large High Altitude Air Shower Observatory on
the eastern edge of the Tibetan Plateau began operating
in April. Located some 4,400 meters above sea level, the
observatory will study high-energy cosmic rays.