I wrote this for a fundraising event in
December 2009. Its a short history of the attempts to make lifelike robotics and
animatronics. If one of the you
tube links stop working,
please let me know.
we look at the things around us, we canít help trying to see everything
as a face. The protractor is obviously a happy protractor and the mole
grips look hungry. Three dots are enough to make a face, itís the first
pattern babies recognise.
The reason we see faces everywhere is that our brains
are particularly sensitive to them. Our eyes are really quite crude
sensors, its our brains that put the limited information together to make
a convincing perception of the world around us. The basis of most optical
illusions is the mismatch between the limited information coming from the
retina with the huge assumptions made by the brain.
reason we see faces everywhere is that our brains are particularly
sensitive to them. In our evolution its been very useful to be able to
recognize individuals, and be sensitive to their mood. This is what makes
us Ďseeí faces in everything. Even people who say they arenít
observant effortlessly recognize their friends and judge their moods. But
our sensitivity to faces also makes us particularly observant at spotting
subtle differences between a real face and a waxwork or robot. This talk
is about the quest to make a human replica completely convincing.
The title of my talk comes from Masahiro Mori, who
was professor of robotics at Tokyo university in the 1970s. He produced a
graph he called the uncanny valley. His idea is that industrial robots
donít look very human and so arenít seen as friendly or possessing any
emotion. Making robots appear more human, we can see them as more
friendly. Make them too lifelike though and they start to be creepy. At
the pit of his graph, the creepiest thing imaginable, he places a moving
real dead body. (He came up with his graph after the shock of shaking
hands with someone with a prosthetic arm).Halfway up the slope up towards totally accepting reality he puts
ill people, handicapped people and Bunkaru puppets. Itís
over simple, because people vary enormously in what they find creepy.
partly interested because a lot of people find my arcade
in southwold creepy, including my grandson. My chiropodist was
inspired by a strict nurse with a brisk efficient manner, but I overheard
some describing her as a zombie last week. I still donít see her as
uncanny, though I know others do. The uncanny valley graph has its
limitations but its a great title and I think the quest to create a
convincing human replica is a great subject.
On the left is the Dagenham idol, the earliest known
depiction of a human ever found in Britain. Not at all lifelike, but our
brains completely accept that it was intended to be a human figure. The
first step towards the uncanny valley was to get the overall shape right.
I think it was the ancient Greeks who first did this Ė this is partly
why we admire their statues so much. They were interested in an abstract
idea of beauty. However, the Romans were the first to capture lifelike
Ďportraitsí of specific individuals (see right). Their portraits were originally
painted, so they would have looked a lot more Ďrealí than they do now.
Progress is complicated because in the middle ages,
people werenít generally interested in realism. But it came back with
the Renaissance, this16th century Spanish Christ
is made of covered in gesso with ivory teeth and glass eyes is an example.
But stone and wood can never look really convincingly
like skin. Skin is translucent, so some of the colour comes from below the
surface. It also has hairs and a fine surface texture. A better material
for copying skin is wax. By the 19th century Ďwaxworksí,
which people paid to visit, had become popular. The appeal was the spooky
realism of the figures, some of them death masks of criminals. Its amazing
that they still thrive today because of our obsession with celebrity.I love the publicity photos Madame Tussauds, London, take of the
celebrities standing by
their waxwork. You can always tell which is real.
I think the convincingness of waxworks has more to do
with how they are viewed than how beautifully they are made. Madame
Tussaudís has always had a wax security guard sitting by the door Ė I
enjoy this more than the celebs because its unexpected. The ultra
realistic figures made by the artist Duane Hanson are effective because
they merge with the gallery visitors.
Wax remained the most lifelike material for skin
until the 1960s, when silicon resins became available. A big advantage is
that silicon can be moulded from real skin to faithfully reproduce its
fine texture and also that its easy to thread fine hairs into silicon. The
artist Ron Muek uses silicon for many of his figures. Ron is a great
craftsman and his body shapes, faces and skin texture are often completely
convincing. Dead Dad, who is half size, is certainly down there near the
bottom of the uncanny valley. But for me, heís not quite at the bottom. Ronís figures, though they look so real, never
moveÖ... moving replicas are much more creepy.
Making a moving realistic realistic figure is much
harder. Their are many myths about them. The golem is a jewish
giant with many stories attached to him, always fashioned from clay. The
giant Talus, made of brass, is said to have guarded Crete against
intruders by heating up his body and hugging them to death. His only
vulnerable spot was his right ankle, which had a sinew of flesh and a vein
of blood. Thereís a bone in the ankle still named the Talus.
Though creating lifelike movement is hard, people
obviously have an innate fascination because over the centuries an enormous amount of much effort has
gone into it. It was easier to start
small. The first
practical moving figures were possibly Heronís simple ancient Greek automata,
powered by water. Next were the medieval clockmakers, using clockwork to power
complicated automata. They were made from the 17th century
onwards as one offs for the extremely rich. By the 19th century
France had quite an industry making clockwork automata. The video is
rather slow but it gets increasingly creepy. The automata
were always small, so they werenít quite as creepy as you might
donít really understand why clockwork canít be scaled up, though it
obviously canít be as all clockwork mechanisms are small.
The goal of a full size human replica remained remote
until people started playing with electricity in the 18th
century. As they got electric shocks, they quickly realized that we are
affected by the stuff. But the key experiment linking our bodies to
electricity was done by Galvani. His classic experiment was to make
frogsí legs twitch (see all the frogs legs in his lab, above). I later found that he also tried it on
chickens and dead human bodies. Reports of his experiments
are partly what inspired Mary Shelley to write Frankenstein.
time, no one knew enough about electricity to put it to any practical use,
but it certainly made the idea of replica humans more Ďhigh profileí.
Depictions of steam powered men and servants became common.
100 years later small motors and relay logic (to
switch combinations of the motors on and off) made it finally possible to
construct a crude mechanical man. Electro the smoking robot was inspired by
the Czech play RUR, which coined the word Ďrobotí. Robots quickly
gained popularity, and began to be made as toys, to be collected, and to
star in films and comic strips.
There were still formidable problems to make anything
remotely realistic. The first problem is the jerkiness of the movements.
When we move our arms several different muscles stretch or contract and
they smoothly work together at constantly varying speeds. The
ĎRoboticí jerky movement of early robots that are still performed by
mime artists come from the motors and pistons, which naturally move at constant
Computers have helped to smooth the motion. Industrial
robots now have sensors in all their joints to provide feedback to the
computer and this controls the speeds and accelerations of the motors. This gives them fluid
multi axis movements which can be very balletic. Though the movement looks
effortless, robot arms require a lot of precision parts and fast
computing, so one like this costs at least£100,000. They are now so reliable that people trust
them with their life.
Practical robots are no longer mechanical men, they
have become completely functional. Robot researchers now tend to be more
interested in mimicking animals than humans. Many legs is easier than just
Its no problem getting a robot to walk if it has
something solid to hold to "support" it. This robot man was a seaside attraction in
the 1950s. Without a prop
like his carriage, walking is hard. We walk without thinking, but keeping
in balance while moving the top heavy weight of our head and body is
actually an amazing feat. As we walk we are subconsciously and constantly adjusting our balance. Robots have great trouble reacting as
fast as we can. As far as I know, no robot can catch a ball. A japanese team has
been trying to get a robot to juggle, but so far it canít react fast
enough. This is a robot made
by Honda for research. It cost millions.
Most recent attempts to make humanoid robots don't
attempt walking because
its so hard. One of the reasons Iím interested in the uncanny valley is
thata fiend of mine called
Will Jackson has been developing a robot for the last 5
years. Called Robothespian, it is mainly sold to science centres to greet
visitors and perform in their Object theatres. Itís
engaging, particularly because of its eyes, which are two mobile phone
display screens each showing video of an eye. I
think its quite friendly, but Iím sure some people find it very uncanny.
Unlike most robots, Robothespian's limbs are íair
musclesí. These are rubber tubes which simultaneously swell in girth and
contract in length when fed with compressed air. The advantage is that
unlike ordinary pneumatic cylinders, the amount of movement is
proportional to the pressure applied.A computer moves and positions every air muscle using proportional
pressure air valves. The drawback is that the movements arenít precise.
Robothespian currently has trouble getting fingers of both hands to touch, though
its really impressive how Will is continually improving it. Willís
struggles have made me aware of just how much I take for granted about the
seemingly effortless way my body moves about.
Even if you get the movement right, to make something
really lifelike thereís the
skin problem. With old automata, the leather and fabric quickly cracked up
because of the movement. Today silicon rubber can stretch to some extent, but it needs to
be very thin to stretch as much as skin. If its thin, it doesnít keep
its shape and also tends to tear. There's no perfect plastic for skin, so
animatronic figures usually have rather limited facial movements.
Disney imaginers have been making "realistic"
animatronic figures since the 1960s. Disneyworld, Florida, has a hall of
presidents, each of which gesticulates and says something in turn. They
have PVC skin, with stage make-up on top. The necks unzip at the back to
get at the mechanisms inside. From the front they look convincing, but
they are seen in low light and seen at some distance. To move the arms,
they use hydraulic pistons, miniature versions of the ones on diggers.
Hydraulics tend to leak oil, so you never see the platform the figures are
standing on. Personally, I found the seriousness of the presidents
presentation made them more funny than creepy.
Disney is secretive about their technology Ė they
have never patented anything for fear of having to expose their secrets in
the patent application. However they have competitors who are quite happy
to let people take photos. The Sally corporation makes anything from Greek
goddesses to the undead. The Sarcos corporation does the same. Although
Sarcos primarily makes animatronics for theme parks, it also makes
sophisticated sensors and prosthetic arms. Animatronics also completely
overlap with research.
The most creepy of the animatronics companies is the
Hanson Corporation. Their technology is based on their skin material they
called flubber. Jules is their creation. They deliberately didnít add a
back to his head just so you know he isnít real. He looks as if heís
had too much botox to me.
However, technology keeps moving on and Darpa, the
American military research funding organisation that came up with the
internet and the computer mouse had been busy funding walking robots. This
is Big Dog, made by Boston Dynamics, founded by the genius Mark Railbert,
who also started MITs leglab. To me, though this doesnít look remotely
human, it is really uncanny, right at the bottom of the valley. Amazingly,
though the basic leg movements are high pressure hydraullics, the
reactions when it falls come mainly from huge springs, not some high tech
Thatís the end of my voyage to the uncanny
valley. Though Iím fascinated by all the clever projects Iíve shown
you its not a direction I'm tempted to go myself. Its
so hard to make something really lifelike, I'm happy to stick with my
unrealistic 'cartoon' figures. A
wonderful feature of our brains is how quickly we can forget that
something isnít real. When a film starts I am completely aware of the
auditorium and, if itís a foreign film, also of reading the sub titles.
But if the film is any good, I quickly become totally immersed in the
story and forget about the reality of the situation. We are so lucky to
have brains that can both do amazing things like Mark Railbert and equally be
capable of suspending belief and enjoying a good story or accepting
a protractor as a face.