Speaker 1: Welcome to Brainstuff from how stuff Works dot com where
Speaker 1: smart Happens. Hi. I'm Marshall Brain with today's question, how
Speaker 1: do self driving cars work? Who wouldn't like to have
Speaker 1: a car that drives itself. The idea of being able
Speaker 1: to sleep or to use your laptop during the commute
Speaker 1: to work is certainly appealing. The idea of having your
Speaker 1: car drop you off at the door of a store
Speaker 1: and then go park itself is also attractive. And then
Speaker 1: there's the safety thing. Human beings just are not that
Speaker 1: good when it comes to driving, with millions of automobile
Speaker 1: accidents causing damage, injury, and death every year. If we
Speaker 1: all had self driving cars, it would be great. Two
Speaker 1: recent announcements have made self driving cars seem a lot
Speaker 1: closer to reality. The first comes from the Army, which
Speaker 1: is now using self driving vehicle to guard a large
Speaker 1: military facility and nuclear waste dump in Nevada. And then
Speaker 1: there's Google, which recently announced that it's developed self driving
Speaker 1: cars that have logged over a hundred thousand miles on
Speaker 1: real roads in real traffic. What's going on inside these
Speaker 1: cars to make it possible for them to drive themselves.
Speaker 1: We can take a look at it. By looking at
Speaker 1: Google cars or some of the cars that have participated
Speaker 1: in DARPST Grand Challenge, you could, in theory, turn any
Speaker 1: car into a self driving car. The first thing you
Speaker 1: would have to do is make it possible for a
Speaker 1: computer to control the car. This is not quite as
Speaker 1: easy as it sounds, but it's relatively straightforward. The computer
Speaker 1: needs to be able to turn the steering wheel, push
Speaker 1: the accelerator and brake pedals, move the gear shift control,
Speaker 1: and start the engine. These tasks, at least in experimental
Speaker 1: self driving cars, are often accomplished with electric motors. A
Speaker 1: motor is mounted so it can turn the existing steering
Speaker 1: wheel for example. Another motor is able to put pressure
Speaker 1: on the accelerator and brake pedals and so on. It's
Speaker 1: not a particularly elegant solution, but it gets the job done.
Speaker 1: As production cars become more advanced, drive by wire systems
Speaker 1: are becoming a lot more common, So in a like
Speaker 1: a Prius a Toyota Prius, if you push the brake pedal,
Speaker 1: it might go to a computer and the computer actually
Speaker 1: activates the brakes. There's no direct mechanical linkage between the
Speaker 1: brake pedal and the brake mechanism that's called drive by
Speaker 1: wire when the computer is sitting there in the middle.
Speaker 1: In cars with drive by wire, a computer can hook
Speaker 1: directly into that existing control system without having to have
Speaker 1: these motors hanging out in the driver's area. The next
Speaker 1: thing that a self driving car needs is sensors, and
Speaker 1: here things get pretty complicated. Today, a human being drives
Speaker 1: his car by using his or her eye is as
Speaker 1: the soul sensor. The human visual system is amazing in
Speaker 1: this regard because it's able to accurately judge the presence
Speaker 1: of obstacles, their distances, their relative size based on distance,
Speaker 1: their speed, and so on. A human being also recognizes
Speaker 1: what he or she is seeing, So if a human
Speaker 1: being sees a fence, you can accurately predict with high
Speaker 1: certainty that that fence is not going to jump out
Speaker 1: into the middle of the road and do something to you.
Speaker 1: On the other hand, if there's a child playing with
Speaker 1: a ball on a sidewalk, it's a completely different story,
Speaker 1: and humans can recognize that instantly. Computer vision systems are
Speaker 1: nowhere near this point in their development, so they rely
Speaker 1: on extra sensors to provide more information. Self driving cars
Speaker 1: do have camera based vision systems, and they use it
Speaker 1: to see other cars, unexpected obstacles, road marking signs, and
Speaker 1: so on. But in addition, self driving cars almost always
Speaker 1: have GPS sense, or so they have a better idea
Speaker 1: of exactly where they are and where they're pointing. They
Speaker 1: also have light our systems laser scanners that can look
Speaker 1: for nearby objects and accurately judge their distance. They also
Speaker 1: have radar systems normally, and they may have infrared sensors
Speaker 1: to improve night vision. These sensors all feed into a
Speaker 1: powerful onboard computer, often multiple computers that are usually located
Speaker 1: back in the back catch area of the trunk. They
Speaker 1: could fill an entire trunk in fact, and these process
Speaker 1: all the data that the sensors are gathering. The internal
Speaker 1: computer will have access to a database of maps and
Speaker 1: other relevant information as well. For example, engineers may pre
Speaker 1: drive or route and pre catalog all the signs, road markings, curves, crosswalks,
Speaker 1: traffic lights, and so on that the self driving car
Speaker 1: will encounter along the road. This way, the car knows
Speaker 1: what to expect and complan accordingly. Finally, the onboard computer
Speaker 1: may also be communicating by radio, with bigger computers holding
Speaker 1: even more data in nearby buildings. You might wonder why
Speaker 1: the driving task, which seems effortless to just about any
Speaker 1: normal human adult, would be so hard for a computer.
Speaker 1: It's because the human brain is deceptive. Although it's small
Speaker 1: and silent compared to a desktop computer, the human brain
Speaker 1: still has more power than mankind's biggest fills a whole
Speaker 1: building supercomputers. The massive amount of computing power in the
Speaker 1: human brain is what makes driving appear to be so
Speaker 1: easy for us. In thirty or forty years, our computers
Speaker 1: will have that same kind of power in a small
Speaker 1: package if things keep progressing at their current rate. Be
Speaker 1: sure to check out our new video podcast, Stuff from
Speaker 1: the Future. Join how Stuff Work staff as we explore
Speaker 1: the most promising and perplexing possibilities of tomorrow. The Housuffork's
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