depth perception that’s similar to a human
being’s. This information is used to create
a three-dimensional map of the surround-
ings every few centimeters; the images
are then tied together to create a route,
explains Jeff Christensen, Seegrid’s vice
president of products. The AGVs replay
the route from their memory and follow
it precisely. Changing the route is a simple
matter of taking them on another “walk.”
While each navigation method has its
advantages, each has some drawbacks, too.
For wire guidance, the principal drawback
is that paths are fixed and cannot be easily
changed, since they require cutting into the
floor. Magnetic tape paths are also fixed
but can be changed with comparatively
little time and expense.
The more technologically complex navigation systems also have some constraints.
Vision-guided AGVs, for instance, need
a certain level of ambient light, and their
cameras and lenses aren’t suited for cold
environments. As with human vision, the
farther away an object is, the harder it is to
judge that distance. Laser and lidar users
praise their accuracy, but if lasers from
two vehicles point at each other, they can
in effect blind each other’s sensors, a phenomenon known as dazzling interference,
Christensen says. Similarly, bright sunlight
has been known to interrupt the images
and compromise data gathering in natural-feature and vision guidance systems,
Carlson says. Plus, natural-feature technology would be ineffective in environments
where there are frequent changes or few
permanent features or structures to navigate off of, she adds.
BLAZING NEW TRAILS
Can AGVs get any more sophisticated
than they already are? The vendors we
spoke with for this story believe that more
advances in navigation technology are just
over the horizon. For example, innovations
in image-sensing technology for consum-
er applications will benefit AGV design,
says Seegrid’s Christensen. The availabil-
ity of more-sensitive image sensors that
provide exceptionally high-quality imag-
es in less-than-ideal conditions continues
to grow. His company’s vehicles, for
instance, will soon be able to take high-res-
olution pictures in lower light because of
such advances.
New developments in navigation
are one reason AGVs are moving
more deeply into warehousing, dis-
tribution, and supply chain appli-
cations, AutoGuide’s Carlson says.
She also predicts that navigation
systems that allow users to control a
small fleet of AGVs through an app
on a mobile device without a costly
software installation will make these
vehicles affordable and feasible for
smaller companies.
The new navigation technologies
will help customers participate in
and take advantage of Industry 4.0,
the “fourth industrial revolution,”
characterized by the acquisition,
analysis, and consumption of real-
time operational data, says Drexler
of Clearpath Robotics. “That’s
where I see the industry going—
moving more away from the focus
on hard goods and more toward the
utilization of real-time data.”
Advances in autonomous cars
and trucks are likely to influence
material handling AGVs in the
future, all agree. “AGVs have been
around a lot longer, but autono-
mous cars are a really big story in a
much bigger sphere than warehous-
ing, so there will continue to be a lot
more discoveries and development
in that area,” Christensen says.
“[Automakers] can learn something
from autonomous industrial vehi-
cles, and we can learn some things
from what they’re doing.”
Drexler, for one, believes AGVs
will have an edge over autonomous
highway vehicles. “We believe the
adoption rate for self-driving vehicles will accelerate faster indoors
than outdoors,” he says. Otto
Motors, he adds, is currently on
track to surpass Google’s self-driving car in the number of autonomous miles driven by the end of
next year.
