As the
RoboCup Humanoid League moves from less demanding competitions to soccer games,
the complexity of behavior control increases significantly.
In this
paper, we describe the design of the behavior control software for the Humanoid
League team NimbRo. The
control software is based on a framework that supports a hierarchy of reactive
behaviors. It is
structured both as an agent hierarchy (joint - body part - player - team)
and as a time hierarchy. The speed of sensors, behaviors, and actuators
decreases when moving up in the hierarchy. The
lowest levels of this framework contain position control of individual joints
and kinematic interfaces for body parts. At the
next level, basic skills like omnidirectional walking, kicking, and getting-up
behaviors are implemented. These
are used by soccer behaviors like searching for the ball, approaching the ball,
avoiding obstacles, and defending the goal. Finally,
on the team level, the robots communicate via a wireless network to share
information about the world state and to negotiate roles like attacker and
defender.
Our
robots performed well at the RoboCup 2006 competition, which took place in
Bremen, Germany. The KidSize robots won the Penalty Kick competition and came
in second in the overall Best Humanoid ranking, next only to the titleholder,
Team Osaka.