Putting It to
the Test: The Robot's First Exposure to the World:
What should
happen when we place a baby robot in the world for the first
time?
After
thinking about it, I'm thinking that many of the connections
which we are so obvious that we take them utterly for granted
must be part of extensive and intensive early learning on the
part of an infant. For example, there is the concept of
"solid", and the relationship between open space
and our ability to move through it freely, versus objects
through which we can't move freely.
Presented
with a meaningless blur, how can the robot learn the concept of
"objects"?
The first
thing the robot's brain will have to do will be to generate a 3-D
map. It will do this by by triangulating on the features which it
has detected and has registered frame by frame as it moves
around. This "restlessness" will be pre-programmed.
The robot
will be attracted toward the most "interesting"
featuresfeatures which move, features which make sounds,
features which are brightly colored. This kinetropism,
phonotropism, and chromotropism will be instinctivethat is,
pre-programmed. Also, the robot will be excited and experiencing
what in a living organism would be pleasure. Its clock rate will
be up, its self-appraisal will be positive (whatever we can make
that mean), and it will be totally absorbed in its exploration.
The infant robot will have no emotional defensesno parent
part, no ability to repress, and no real ego. Sensory inputs will
be at full volumeuninhibited. Everything will be recorded,
set up in unique categories, cross-correlated (at first only on
the basis of temporal proximity), and stored at full detail (see
below for a discussion of "full detail"). At this
stage, it will be driven by pre-programmed urges. It will be
drawn to the first, most colorful feature it sees. Here, we
encounter the first disconnect. How does the computer establish a
connection between desire and motor output? I am envisioning a
platform with four-parallel-wheel steering so that it can move in
any direction it pleases. One could make it flail around, like an
infant, until it learns to coordinate its motor activity.
However, motor activity itself must be associated with desire to
move in certain ways. It may be that this instinct may have to be
pre-programmed at least the first time we try it.
It will try
to grasp the feature, if the feature is reachable. Here again, it
must somehow have learnedto coordinate its manipulators so that
it can reach and grasp objectsbefore it can grasp anything. Once
the robot has examined a reachable, handle-able
feature/objectfelt its weight and its shape, squeezed it,
banged it to see what noise it makes, heard its name, (if we want
to give it names even at the outset) and examined it on all
sidesthen, for its first level of understanding about the
world, it will consider the feature known andwill lose interest
in it, moving on to the next feature. It will store a tactile map
together with its visual imagery. In the animal kingdom, for
obvious reasons, a short attention span prevails among the young
of all species so a short attention span will be pre-programmed
into our baby robot. (It will grow out of this when it grows up.)
If the feature is not "handle-able", then the robot
will examine the feature from all available directions and move
on. If the feature changes, either while it is conducting its
exploration or before it sees the feature/object again, then it
will re-examine the object. If the object changes during its
first examination, it will tentatively associate the change with
whatever else is going on at the same time. If the same sequence
of events occurs repeatedly or simultaneously, then the robot's
little mind will establish a causal link between these events and
the change in the object for potential subsequent prediction of
this change. The robotic mind will constantly be seeking
associations between events and/or objects, and at the same time,
it will be correcting or refining these correlations, given
inconsistent sequences of events. This will permit it to predict
a change in the object, given the beginning of the associated
sequence.
If the
object is unchanging, then each successive time the robot
encounters the object, it will spend less time examining the
object than it has before. (Repetitive reinforcement is very
important and comforting to infants and may have to do with
wicked surprises in the world.)
The
learning of general concepts and strategies must be an important
part of the initial exploration of the world. Concepts like
gravity must to be learned, and must present as unwelcome
surprises. (Once a few objects have fallen, an anticipatory
cause-effect pattern from remembered sequences should become
established. "What I tell you three times is true." I
do this, that happens; I do this, that happens.)
Gravity:
When the
robot lets go of something, it will fall to the floor. The noise
should startle the robot (and make an indelible impression). The
robot should then interrupt its environment-exploration program
and pick up the object because it did the unexpected. The robot
would probably re-examine the object, see nothing unusual, and
lose interest, dropping it again. Once again, it would pick up
the object, examine it cursorily (shortening the sequence), and
drop it again. The next (fourth) time, it should more or less
eliminate the examination and should start picking up the object
and dropping it until it becomes evident that it is the letting
go of the object that triggers its fall. An anticipatory sequence
would have been set up, with gradual or rapid elimination of the
examination until only the essence of a cause-effect relationship
would be left. If it were voiced, it might be "I pick up the
object; I let go of it; it falls down and goes boom!"
However, the first time the robot picked up the object, it picked
the object up off the table, so picking it up off the floor is
not a common element. The object won't fall until the robot
releases it, so the releasing of it must trigger the fall. Not
only that but the changing-of location-and-the-noise occurs just
after the moment when the robot releases the object. So releasing
the object becomes the only common denominator and therefore the
probable cause of the change and the noise. (The robot's vision
system may track the object by increasing the update rate to 30
frames a second and the resolution to either one or six minutes
of arc the instant it detects that the object is rapidly changing
location. (The object will move 0.21" then 0.85", then
1.92", then 3.41", then 5.3", then 7.7", then
10.45", then 13.65", and then 17.28", appearing 8
to 9 frames.) The robot would repeat the lifting and dropping
until, after a few trials, it assumed the cause/effect
relationship (in the form of a generic anticipatory sequence).
When the robot has established the expectation that the object
will fall when the robot releases it, the robot will lose
interest in the object. Note the inferences which have been set
up in the form of the anticipatory sequence after three or four
experiments.
A
lower-priority, unsolved puzzle would remain for the robot
regarding why the object hadn't already fallen on the floor but
instead, was sitting on the table when the robot picked it up.
What happens next is negotiable. The robot could defer solving
that puzzle and resume its exploration of its environment. Or it
could follow up, by putting the object back on the table and
observing that the object didn't fall. An adult could lift the
object and put it back on the table and then the robot could try
to imitate it. But how will the robot come up with imitation? It
must first "objectify" its environment. One way to
carry out imitation would be to be to put the robot through the
motions, which it could then replay, as opposed to expecting it
to try to imitate someone else. Another way might be through the
parallel between the robot's recognizing its manipulator and
recognizing someone else's. We might want to begin by using a
manipulator that looked just like its own. It could lift the
object off the table and drop it on the floor. It would do this
several times until it established the consistency of the
results. Then it could play with the object, dropping it from
different heighths and noting the time it took to fall and the
varying loudness with which it hit the floor. It could lift the
object to varying heighths and drop it on the table. It could
slide the object around on the table. It could slide the object
over the edge of the table and discover that the object dropped
without the action of being held and then released. In other
words, it would begin to discover that falling is a behavior of
unsupported objects and not of its releasing the object. One
possibility might be to try to install an expert system for
learning and discovery.