  Heterogeneous Robot Teams can provide a wide range of capabilities and
therefore significant benefits when handling a mission. However, they also
require new approaches to capability and mission definition that are not only
suitable to handle heterogeneous capabilities but furthermore allow a
combination or distribution of them with a coherent representation that is not
limiting the individual robot. Behavior Trees offer many of the required
properties, are growing in popularity for robot control and have been proposed
for multirobot coordination, but always as separate behavior tree, defined in
advance and without consideration for a changing team. In this paper, we
propose a new behavior tree approach that is capable to handle complex real
world robotic missions and is geared towards a distributed execution by
providing built in functionalities for cost calculation, subtree distribution
and data wiring. We present a formal definition, its open source implementation
as ros_bt_py library and experimental verification of its capabilities.
