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Locomoting attractors of self-organized sphere robots
Version 2 2019-03-22, 12:41
Version 1 2019-03-21, 15:42
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posted on 2019-03-22, 12:41 authored by Claudius GrosClaudius Gros, Bulcsú SándorBulcsú SándorWe examine the hypothesis, that short-term synaptic plasticity (STSP)
may generate self-organized motor patterns. We simulated sphere-shaped
autonomous robots, within the LPZRobots simulation package, containing
three weights moving along orthogonal internal rods. The position of a
weight is controlled by a single neuron receiving excitatory input from
the sensor, measuring its actual position, and inhibitory inputs from
the other two neurons. The inhibitory connections are transiently
plastic, following physiologically inspired STSP-rules. We find that a
wide palette of motion patterns are generated through the interaction of
STSP, robot, and environment (closed-loop configuration), including
various forward meandering and circular motions, together with chaotic
trajectories. The observed locomotion is robust with respect to
additional interactions with obstacles. In the chaotic phase the robot
is seemingly engaged in actively exploring its environment. We believe
that our results constitute a concept of proof that transient synaptic
plasticity, as described by STSP, may potentially be important for the
generation of motor commands and for the emergence of complex locomotion
patterns, adapting seamlessly also to unexpected environmental
feedback. We observe spontaneous and collision induced mode switchings,
finding in addition, that locomotion may follow transiently limit cycles
which are otherwise unstable. Regular locomotion corresponds to stable
limit cycles in the sensorimotor loop, which may be characterized in
turn by arbitrary angles of propagation. This degeneracy is, in our
analysis, one of the drivings for the chaotic wandering observed for
selected parameter settings, which is induced by the smooth diffusion of
the angle of propagation