<s>
MIBE	B-Architecture
architecture	I-Architecture
(	O
Motivated	O
Independent	O
BEhavior	O
)	O
is	O
a	O
behavior-based	O
robot	O
architecture	O
developed	O
at	O
Artificial	O
Intelligence	O
and	O
Robotics	O
Lab	O
of	O
Politecnico	O
di	O
Milano	O
by	O
Fabio	O
La	O
Daga	O
and	O
Andrea	O
Bonarini	O
in	O
1998	O
.	O
</s>
<s>
MIBE	B-Architecture
architecture	I-Architecture
is	O
based	O
on	O
the	O
idea	O
of	O
animat	O
and	O
derived	O
from	O
subsumption	B-Architecture
architecture	I-Architecture
,	O
formerly	O
developed	O
by	O
Rodney	O
Brooks	O
and	O
colleagues	O
at	O
MIT	O
in	O
1986	O
.	O
</s>
<s>
MIBE	B-Architecture
architecture	I-Architecture
is	O
based	O
on	O
the	O
assumption	O
that	O
autonomy	O
is	O
grounded	O
on	O
motivation	O
and	O
arises	O
from	O
superimposition	O
of	O
synergetic	O
activities	O
in	O
response	O
to	O
multiple	O
drives	O
.	O
</s>
<s>
MIBE	B-Architecture
architecture	I-Architecture
defines	O
both	O
primary	O
and	O
secondary	O
goals	O
as	O
needs	O
.	O
</s>
<s>
MIBE	B-Architecture
architecture	I-Architecture
generates	O
and	O
weights	O
all	O
these	O
drives	O
in	O
an	O
explicit	O
motivational	O
state	O
.	O
</s>
<s>
MIBE	B-Architecture
architecture	I-Architecture
mainly	O
departs	O
from	O
subsumption	B-Architecture
architecture	I-Architecture
due	O
to	O
the	O
introduction	O
of	O
a	O
top-level	O
motivational	O
structure	O
which	O
determines	O
behavior	O
priorities	O
at	O
run	O
time	O
.	O
</s>
<s>
While	O
subsumption	B-Architecture
architecture	I-Architecture
is	O
built	O
on	O
a	O
predetermined	O
hierarchy	O
of	O
behavioral	O
modules	O
,	O
MIBE	B-Architecture
architecture	I-Architecture
consists	O
of	O
a	O
more	O
complex	O
structure	O
,	O
where	O
several	O
behaviors	O
(	O
that	O
always	O
compete	O
for	O
taking	O
control	O
of	O
the	O
robot	O
via	O
the	O
motivational	O
state	O
)	O
can	O
activate	O
and	O
control	O
dynamically	O
an	O
adaptive	O
set	O
of	O
underlying	O
modules	O
,	O
called	O
abilities	O
.	O
</s>
<s>
The	O
main	O
advantage	O
of	O
MIBE	B-Architecture
architecture	I-Architecture
is	O
its	O
high	O
modularity	O
and	O
molecularity	O
:	O
new	O
abilities	O
and	O
behaviors	O
can	O
be	O
added	O
easily	O
without	O
changing	O
the	O
existing	O
modular	O
structure	O
.	O
</s>
<s>
The	O
main	O
issue	O
of	O
MIBE	B-Architecture
architecture	I-Architecture
is	O
the	O
difficulty	O
of	O
modeling	O
the	O
optimal	O
boundaries	O
of	O
the	O
state-space	O
by	O
shaping	O
the	O
motivational	O
structure	O
(	O
i.e.	O
</s>
<s>
:	O
tuning	O
the	O
drive-generation	O
functions	O
or	O
their	O
learning	O
algorithms	O
)	O
so	O
that	O
the	O
autonomous	O
agent	O
performs	O
the	O
best	O
behavior	O
for	O
each	O
robot+environment	O
state	O
(	O
however	O
the	O
same	O
difficulty	O
also	O
concerns	O
the	O
development	O
of	O
autonomous	O
agents	O
based	O
on	O
subsumption	B-Architecture
architecture	I-Architecture
,	O
although	O
the	O
static	O
hierarchical	O
dependencies	O
between	O
behavioral	O
modules	O
make	O
them	O
a	O
bit	O
easier	O
to	O
set	O
up	O
)	O
.	O
</s>
