research in cognitive development

bouncerarcheryAI and Robotics

Nov 14, 2013 (3 years and 11 months ago)

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The iCub humanoid robot: An open
-
systems platform for
research in cognitive development

Giorgio
Metta

et al.,
Neural networks 2010

윤성재


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Outline


Motivation


Design goals


Foundations of human development


Specific results


Mechatronics of the iCub


Software architecture


Sensorimotor coordination models


Object affordances


Imitation and communication


Conclusion


1


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Motivation


C
onsider
to be a humanoid:


B
iological
-
like system which takes decisions and acts in the
environment.


Adapts
and learns how to behave in new
situations.


Invents
new solutions on the basis of the past
experience.


P
ossibility to interact with it:


To
teach, to demonstrate, even to
communicate.


The developmental process leading to a mature
humanoid.


B
ased
on a road map of human
development.



The main idea is


to
be able to test the iCub in the same manner as
a
developmental


psychologist
would test an infant

in a laboratory
experiment
.


2


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Design
goals


The construction
of cognitive systems could not progress without
a


certain
number of ingredients :


Development
of a sound formal understanding of cognition


Natural cognition and study
of
the development
of cognition


Action
in humans by using neuroscience methods


Physical
instantiation of these models in a behaving humanoid robot



Initial period of human cognitive development and its implementation
on the iCub


Not to preprogram the cognitive
skills
but, similarly to what happens in
hu
mans to
implement them into a system that can learn much like a human
baby does.




3


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Design goals


Considering
action and
embodiment
and how perception and
cogniti
-
on
are intertwined
into development


Exemplar experimental
scenarios
are discovering the action possibilities

of
the body (the so called body map
)


Learning
to control one’s upper and lower body (
crawling
, bending the
tor
-
so
) to reach for
targets


Learning
to reach static and moving targets, and learning to balance in

order
to perform stable object manipulations when crawling or
sitting



Interaction with other agents


Recognizing manipulation abilities of others and relating those to one’s
own manipulation abilities


Learning
new motor skills and new object affordances by imitating
manip
-
ulation

tasks performed by others


Learning what to imitate and when to imitate others gestures


Learning regulating interaction dynamics.


4


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Foundations of human development


To provide
a description of human
development
, we have to consider
three
basic elements:


What is innate, where do we start from?


What drives development?


How is new knowledge
incorporated
?



What is innate, where do we start from?


Developmental psychologists, typically refer to innate elements in terms of
prenatal prestructuring or the so
-
called core abilities.


Motor
system requires constraints in order to reduce the large number of
effective degrees of freedom


These constraints come in the form of muscular synergies. To facilitate
control, the activation of muscles is therefore organized into functional
synergies at the beginning of life


Prestructuring comes also in the form of specific core abilities.




5


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Foundations of human development


What drives development?


Motivations
come in different forms in the newborn: social and explorative.


Social
motive
is providing
further possibilities for learning, safety,

com
fort
, etc
.



How is new knowledge incorporated?


Final product is shaped by the dynamical interaction with the
environment.
The
brain is only one side of this
process


Factors like exposure or deprivation to the
environment are also important


The
body biomechanics and body growth are all fundamental to the de
velopment of cognition.



6


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Foundations of human development


Neurophysiology
is also helping to show the
complexity
of
the brain
.


Canonical and mirror neurons are indistinguishable.
Their visual responses, however, are quite different.


The canonical type is active in two situations:

(1) When grasping an object and

(2) When fixating that same object


Mirror neuron, becomes active under either of two conditions:

(1)
Manipulating an object (e.g. grasping it, as for canonical neurons)

(2)
Watching someone else performing the same action on the same
object



Two visual pathways


Dorsal & Ventral


Dorsal deals with information
required for action


V
entral
is important for more cognitive tasks such as maintaining

an
object’s identity and constancy



7


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Mechatronics of the iCub


1m tall and weighs 22
kg


# of DOF(degrees
of
freedom)


F
or
the upper body
is 38


Each
leg has 6 DOF
(
for crawling, sitting and
squatting)



E
quipped
with
digital
cameras, gyroscopes and accelerometers, microphones
, and force/torque
sensors.

%Distributed
sensorized

skin is under
development
using
capacitive sensors technology



A set of DSP
-
based control
cards. Takes
care of the low
-
level control loop
in
real
-
time.


DSPs
communicate with each other via a CAN bus.


Four
CAN bus lines connect the various segments of the robot.


All
sensory and motor
-
state information is transferred to an
embedded
Pentium
based PC104
card that handles synchronization and
reforma
-
tting

of the various data streams.



8


Specific results

S FT COMPUTING @ YONSEI UNIV . KOREA

16

Sensorimotor coordination model


Cognitive
capabilities depend greatly on the
development
of
sensorimotor


coordination
and sensorimotor mapping.


E
xperience
enters into the process in forming reliable and
sophisticated
tools
for exploring and manipulating the outside world.



The research on sensorimotor coordination has two distinct themes.


Modeling Sensorimotor
systems evolve from sets of
relatively
independe
-
nt

mechanisms
to unified functional systems.


Modeling
the role of motor representation as tools serving not
only action
but also perception
.




L
ayered
controller system for the iCub including:

1.
Spinal
behaviours

2.
Eye movements and attention

3.
Reacting and body schemes

4.
Grasping




9


Specific results


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Object affordances


The term affordance
is


‘‘Action
possibilities’’ on a certain
object


E.g.) A
chair
is ‘
‘sit
-
able’’ for a perceiver


Humans learn to exploit object affordances throughout their entire life
but not all are learnt autonomously.


A
large set is
conveyed
by social means either by communication or
by
observing others actions.


Difficult
to separate the importance of learning by exploration and learning
from others.


D
istinguish
two means of acquisition of
object
affordances
:


S
elf
-
exploration (
autonomous
learning
)


B
y
observation (learning from examples
)


10


Specific results


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Object affordances

1.
System
has acquired the capability to coordinate
movements with
respect to sensory
information.


2.
It
can start interacting with objects and understanding its
interface
(
autonomous learning
)


How
to grab the object, what are the effects of certain applied actions.


3.
System
may start
recognizing
and interpreting
other agents (
learni
-
ng

from
examples)


I
nteracting
with similar
objects
, learning other object affordances and
inte
-
rpreting

activities.


11


Specific results


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Object affordances


Use
Bayesian Networks (BN
) for
learning
affordances.


Model
the dependencies between robot actions, object characteristics,

and
the resulting effects








A
ffordances
can be learned
autonomou
-
sly
by experience and by
self
-
observatio
n. Features
can be either selected
or
ignored



12


Specific results


S FT COMPUTING @ YONSEI UNIV . KOREA

16


Experiments


Playground
scenario consisting of several objects with two shapes

(
box and ball), different
sizes.


iCub
was able to perform three different actions: grasp, tap and touch.


Results
show how the model is able to capture the basic object
beha
-
viour

under different actions
.


Relations
are shaped by the experience of the robot and by its current skill
s.




Object affordances

13


Specific results


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Imitation and communication


Imitation
plays a central role and
communication.


Particular
concern here are
cognitive
skills required for communicating

through
body
gestures.



Large part of this iCub work took a human

robot interaction perspecti
ve to analyzing and developing controllers to enhance human

robot
communication.



Relies on sophisticated cognitive skills which requires


Recognize and interpret somebody else’s gestures in terms of its own
capabilities (mirror effects),


Learn new gestures


Recognize the purpose of other people’s gestures


Predict the result of a demonstrated manipulation task


Finally, the ability to decide what part of the demonstration is relevant to
imitation



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Specific results


S FT COMPUTING @ YONSEI UNIV . KOREA

16

Conclusion


Forefront research in developmental robotics, the
iCub

was designed
completely from
scratch of


M
echanics
,
electronics
, firmware, and software


Multisensory neurons connection


Brain
is not made of a set of isolated areas dealing with perception or
mo
-
tor control but
rather that multisensory
neurons.


Computational model of affordances


Quintessential primitives of cognition by mixing perception and action in a
single
concept


Includes the possibility of learning both the structure of dependences bet
-
ween

sets of random variables


Facilitating the creation of a computation model of imitation and inter
-
action between humans and robots


By evaluating the automatic construction of models from experience, their
correction via feedback.


Explores the domain between mere
sensorimotor

associations and the
possibility of true communication between robot and people.


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