conditions. The Google project has
made important advances over its predecessor, consolidating down to one
laser rangefinder from five and incorporating data from a broader range
of sources to help the car make more
informed decisions about how to respond to its external environment.
“The threshold for error is minuscule,” says Thrun, who points out that
regulators will likely set a much higher
bar for safety with a self-driving car
than for one driven by notoriously er-ror-prone humans. “Making a car drive
is fundamentally a computer science
issue, because you’re taking in vast
amounts of data and you need to make
decisions on that data,” he says. “You
need to worry about noise, uncertainty, what the data entails.” For example,
stray data might flow in from other
cars, pedestrians, and bicyclists—each
behaving differently and therefore requiring different handling.
Google also has a powerful tool to
help Thrun improve the accuracy of
his driving algorithms: Google Maps.
By supplementing the company’s
publicly available mapping data with
details about traffic signage, lane
markers, and other information, the
car’s software can develop a working
model of the environment in advance.
“We changed the paradigm a bit toward map-based driving, whereby we
don’t drive a completely unknown,
unrehearsed road,” Thrun explains.
Comparing real-time sensor inputs
with previously captured data stored
at Google enables the car’s algorithms
to make more informed decisions and
greatly reduce its margin of error.
Although the trial runs are promising, Thrun acknowledges that the cars
must be put through many more paces
before the project comes anywhere
close to market readiness. He freely admits the Google car is a long way from
rolling off an assembly line. “We are
still in a research stage,” says Thrun,
“but we believe that we can make these
cars safer and make driving more fun.”
At press time, Google had hired a
lobbyist to promote two robotic car-related bills to the Nevada legislature.
One bill, an amendment to an existing
electric vehicle law, would permit the
licensing and testing of self-driving
cars. The second is an exemption to allow texting during driving.
“Making a car drive
is fundamentally a
taking in vast
amounts of data
and you need
to make decisions
on that data.”
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