For years, technology companies have promoted the idea
that cars could be outfitted with the same kind of "black box"
technology that aircraft had. A device would record information in the
event of an accident and reveal movement, direction, angle and other
data. I first wrote about the concept for MIT Technology Review
six years ago, and quoted the CEO of a company manufacturing so-called
"event data recorders" who optimistically but incorrectly believed they
would first appear in the 2007 model year.
In hindsight, it's easier to see that what may bring these "black
boxes" closer to reality are the three-axis accelerometers coming onto
the market. STMicro is the latest to release such a device, which
measures movement in multiple directions; Freescale and Hitachi have
already released three-axis accelerometers.
STMicro says the AIS326DQ
accelerometer is the first of a range of products as part of its
strategy to expand its business in consumer MEMS to automotive
applications. Marco Ferraresi, Automotive Unit Business Manager for
STMicro cites potential applicability for the new accelerometer in
vehicle alarms, tracking and monitoring, seat controls, navigation and
antenna positioning, as well as black-box capabilities. The new
accelerometer can also be used in applications such as vibration
monitoring in heavy-duty equipment and shipping-container security.
STMicro will initially target Tier 1 and Tier 2 manufacturers in the
automotive industry as well as aftermarket alarm manufacturers.
Ferraresi would not reveal the names of any customers, other than to
say he was negotiating with both U.S. and EU manufacturers.
Ferraresi says the new device offers more flexibility in terms of
where it's located in an automobile. "A two-axis accelerometer has to
be mounted properly, to ensure that it directionally aligns with the acceleration the application needs to measure. You can mount a three-axis device anywhere."
He says the STMicro device has an adjustable range between ± 2g and
± 6g in any direction; that allows manufacturers to adjust its
sensitivity. "This is a very powerful device, but you need to find the
right tradeoff so that a false event does not trigger the alarm. The
manufacturers can program it to filter out accidental bumps."
Ferraresi says there are other potential applications to drive
deployment of accelerometers in vehicles. "If you lose the GPS signal -
for instance, when you're in a tunnel - you can still use the
accelerometer to track the movement of the car," he says, citing the
need for this capability both for stolen vehicles and for shipment
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