  Traffic collision avoidance systems (TCAS) are used in order to avoid
incidences of mid-air collisions between aircraft. We present a game-theoretic
approach of a TCAS designed for autonomous unmanned aerial vehicles (UAVs). A
variant of the canonical example of game-theoretic learning, fictitious play,
is used as a coordination mechanism between the UAVs, that should choose
between the alternative altitudes to fly and avoid collision. We present the
implementation results of the proposed coordination mechanism in two
quad-copters flying in opposite directions.
