  Many multi-agent systems in nature are comprised of agents that interact
with, and respond to, the dynamics of their environment. In this paper, we
approach the study of such agent-environment interactions through the study of
passively compliant vehicles coupled to their environment via simple
nonholonomic constraints. We first consider a single passively compliant
Chaplygin beanie atop a platform having translational compliance, introduce the
reduced equations for the system using the notion of nonholonomic momentum, and
provide proof for its stability under arbitrary deformations of the elastic
element modeling its compliance. We then direct our focus to results concerning
the frequency response and control of passive Chaplygin beanies under actuation
of the platform, discuss rich dynamical features arising from periodic
actuation, and develop rules by which control can be exerted to collect and
disperse multiple passive vehicles. We then discuss how the latter of these
results clarifies the extent to which stable behavior can be excited in the
system through exogenous control.
