Figure 21. Perceived scenario of an animat.
Expression (20) simulates a short-medium term memory. The “remembered” stimuli
conform the animat’s “remembered scenario”. All the stimuli found in the perceived and
remembered scenarios are registered in BeCA by the exteroceptors.
5.3.2. The internal medium
The internal medium is defined by a set of variables which can take values between zero
and one, representing strength, lucidity, safety, fatigue, thirst, and hunger. The size of the
angular steps of the animat is proportional to his strength, while his radius of perception is
proportional to his lucidity. The safety value does not change in time; but fatigue, thirst and
hunger are increased in time (or decreased if a proper consummatory behaviour is executed).
When these last three internal needs are high, strength and lucidity are decreased, and when
they are low, strength and lucidity are increased. When strength is equal to zero, the animat
dies. A prey animat might also be killed by a predator, which feeds himself decreasing the
prey’s strength value. When this reaches zero, predators cannot longer feed themselves from
the hunted prey.
The internal medium of the animats is perceived by the interoceptors of BeCA.
5.3.3. The motor system
The animat’s movement is commanded by angular steps " and $, with a centre in the
extremes of the diameter of the projection of the sphere of the animat in the plane (z, x), as
shown in Figure 22.
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