Trading Control Intelligence for Physical Intelligence: Muscle Drives in Evolved Virtual Creatures

Traditional evolved virtual creatures [12] are actuated using
unevolved, uniform, invisible drives at joints between rigid
segments. In contrast, this paper shows how such conven-
tional actuators can be replaced by evolvable muscle drives
that are a part of the creature’s physical structure. Such a
muscle-drive system replaces control intelligence with mean-
ingful morphological complexity. For instance, the experi-
ments in this paper show that control intelligence sufficient
for locomotion or jumping can be moved almost entirely
from the brain into the musculature of evolved virtual crea-
tures.
This design is important for two reasons: First, the con-
trol intelligence is made visible in the purposeful develop-
ment of muscle density, orientation, attachment points, and
size. Second, the complexity that needs to be evolved for the
brain to control the actuators is reduced, and in some cases
can be essentially eliminated, thus freeing brain power for
higher-level functions. Such designs may thus make it pos-
sible to create more complex behavior than would otherwise
be achievable.