04/03/2000 Design News
Sensors help drivers stay awake
Plymouth, MI-A car that
prevents drivers from falling asleep at the wheel is
much closer to becoming a reality thanks to designers
at Johnson Controls. "The technology is here. We just
need to learn more about sleep patterns," says Bob Munson,
the manager of product planning and business development
at the company.
Johnson Controls equipped a 2000 Lincoln
LS with a Driver Drowsiness Alert System. "We're looking
at different ways of monitoring the onset of sleep,"
says Munson. "One way involves the use of cameras that
watch the eyes of the driver. Another involves monitoring
head nods," he says.
The Lincoln uses vehicle-mounted capacitance
sensors and a microprocessor for monitoring driver behavior.
The capacitance sensors mount in the vehicle headliners.
The system can deliver a variety of warning signals
if the driver begins falling asleep.
"We are working with a sleep lab in Massachusetts,"
says John Eaton, the market segment manager for luxury
cars at Johnson Controls. "We are probably a year or
two away from nailing this system down," he says.
-Bruce Wiebusch, Regional Editor
Detroit-In a setback to
use of so-called zero-emission vehicles, early March
found General Motors recalling its 1997 Generation I
EV1 electric cars and 1997-98 S-10 Electric Trucks.
The company says the vehicles were produced with a charge
port that may fail during charging. If this occurs,
heat could build up within the port and a fire result.
GM's advanced technology group says that although the
small part can be replaced in the pickups, the more
complex EV1 installation precludes repair. The notice
said the company would assist in termination of the
lease, and "discuss your immediate transportation needs."
Generation II, 1999 EV1s were not involved "due to their
uniquely different charge-port design." The company
says electric vehicles are still very important to GM.
Pneumatics pump up drone
Easton, MD-BAI Aerosystems
Dragon Drone unmanned aerial vehicle (UAV) provides
land and sea forces with an ability to do reconnaissance,
at a range of 50 miles for missions up to three hours.
An effective launch system and recovery skids or shipboard
net permitted its designers to cut vehicle weight by
eliminating the landing gear.
But when shipboard launching was needed,
difficulty with the existing launcher became apparent,
according to Jay Willmott, vice president of BAI Aerospace.
Previous launch methods flung not only the UAV out off
the launcher, but its cradle as well. Aboard ship, such
discarding of components overboard was not acceptable.
BAI engineers redesigned their launcher
that retains the cradle around a pair of rodless pneumatic
cylinders from Hoerbiger-Origa (Glendale Heights, IL).
These 80 mm (3.1 inch) bore devices have a 3m (9.8 ft)
stroke and accelerate the 50 kg (110 lbs) drone to 100
kph (62 mph) during launch. The cylinders are first
charged to about 8 bar pressure with bottled nitrogen
or air from a compressor. According to Hoerbiger-Origa
Mechanical Applications Engineer Stephan Barry, once
launched, shock absorbers in the cylinder end caps and
specially machined holes in the cylinder barrel decelerate
the cylinder pistons along with the UAV's cradle. The
shocks directly absorb energy, while the holes bleed
pressure once the pistons pass them.
Willmott says, "Reliability has been excellent,
even in desert environments."
The rodless pneumatic cylinders allow
rapid, successive drone launchings.
-Rick DeMeis, Senior Editor
`Quantum mirage' makes nano-circuits
San Jose, CA-Physicists
at IBM's Almaden Research Center have demonstrated a
working circuit as small as an atom-that's one-tenth
of a nanometer wide-which does not use conventional
wiring. The breakthrough promises to radically change
modern electronics, making for new circuits with a thousand
times the storage capacity of today's chips.
The atomic-sized circuit employs the wave
nature of electrons to transfer data through a solid
in place of wires in a"quantum mirage effect." "We call
it a mirage because we project information about one
atom to another spot where there is no atom," said Donald
M. Eigler, lead project researcher.
As computer circuits shrink to the atomic
level, the behavior of electrons changes from being
particle-like to wave-like. On such small scales, tiny
wires don't conduct electrons as well as classical physics
predicts. So quantum analogs must be available if nanocircuits
are to achieve the performance advantages from their
To create the quantum mirage, scientists
moved several dozen cobalt atoms on a copper surface
into an elliptical shaped ring-"quantum corral"-reflecting
the copper's surface electrons within the ring into
a wave pattern predicted by quantum mechanics.
The size and shape of the elliptical corral
determine its quantum states-the energy and spatial
distribution of the confined electrons. The IBM researchers
used a quantum state that concentrated large electron
densities at each focus point of the elliptical corral.
When the scientists placed an atom of magnetic cobalt
at one focus, a mirage appeared at the other focus:
the same electronic states in the surface electrons
surrounding the cobalt atom were detected even though
no magnetic atom was actually there. The intensity of
the mirage is about one-third of the intensity around
the cobalt atom.
CYBERLAND?Hankerin' for a hang-out?
Then the Engineering Hangout is the place
to be. This is truly a cyber-café for all who are engineers.
The site features freeware, shareware, and demo downloads,
an engineering book club, engineering message boards,
a page of newsgroups just for engineers, puzzles and
games, and a link to lots of free stuff on the Internet.
And if you have some used slide rules you want to get
rid of, the site even features a basement for buying,
selling, and trading. Engineers can sign up for an e-mail
update or fill out an opinion form that changes on a
regular basis. Oh yeah, the URL to be seen at is www.engineeringhangout.com.
HDTV pushes displays to perform
Plano, TX-Does Monday
Night Football have you eyeing your 27-incher and
wishing for a high-resolution big screen to make those
images look like a seat on the 50-yard line? If you're
like many people, you may be holding out on that big
screen purchase. Poor picture quality in today's systems
may be the reason why. Another downside is size-you
may think you have to give up the whole living room
to get good picture quality. And what about HDTV (high
definition television)-isn't it right around the corner?
Crisp image quality, low weight, and portability
have made digital light processing, or DLP, projection
popular in the business market, from ultraportable projectors
for on-the-road presentations to highbrightness systems
used at trade shows. Since the technology was first
unveiled in 1996, the world has become increasingly
digital-with digital image capture, editing, and transmission
seen in high-definition television, 64-bit gaming systems,
digital cameras, and DVD-digital projection seems the
next logical step. This year consumers will see the
launch of large screen, HD-capable home entertainment
systems based on Texas Instruments' DLP technology,
which the company says provides higher contrast, color
accuracy, and sharper video images than liquid crystal
display or cathode ray tube-based systems. The DLP also
offers size advantages, says the company, since it can
be housed in a compact cabinet that is smaller than
the enclosure required for a conventional large screen
"To display all the information which
the family of the future will demand," says Dale Zimmerman,
home entertainment project manager with Texas Instruments,
"the screen will have to be large-which means that the
CRT is unlikely to be able to compete without filling
the entire living room." DLP enables the design of large
screen systems, which can be housed in compact cabinets.
LCD has not yet demonstrated that it can deliver acceptable
video image quality of HD applications. "Plasma is everyone's
idea of the TV on the wall, but it continues to be very
expensive and still has a long way to go in terms of
image quality," says Zimmerman.
Both Mitsubishi and Hitachi will use DLP
technology in all-digital, large- screen, high-definition
rear-projection television, which will go on the market
Texas Instruments' digital light processing
system consists of a light source, optics, color filters,
digital processing and formatting, a digital micromirror
device (DMD), and projection lens. It operates under
an extremely simple principle. The DMD, an optical semiconductor
chip that has 500,000 microscopic mirrors mounted on
a standard logic device, is the heart of the system.
Each mirror represents one pixel. These tiny hinged
mirrors (480,000 SVGA, 786,000 XGA, or 1,310,000 SXGA)
operate as optical switches-either reflecting light
away from the lens (off) or through a lens (on) to create
a high-resolution, full-color image. Electrodes under
opposite corners of the mirror are activated by the
incoming video or graphics signal and cause each mirror
to tilt thousands of times per second. This structure
yields pixels that can switch on or off more than 5,000
times per second in response to incoming digital signals.
Each square micromirror is about 1/5th the thickness
of a human hair. The gap between the mirrors is less
than one micron, giving DLP images a seamless appearance.
Light is either reflected through the lens onto the
screen-in which case a white pixel appears- or away