Currently there is no collision avoidance in the Nao "navigator". Since this causes a lot of penalties, especially when we become more active in the future, we should implement a basic collision avoidance. The best way to achieve this seems to be to use the sonar sensor. It is cheap to acquire and, given that other teams are using it for this purpose, should be precise enough for the task.

In the beginning we could stop the motion in that situation, and possibly turn and walk on. The behavior should be implemented such that it can be switched off via a config flag, if we see that this makes the robot "too careful". Basically the good ol' RoboCup mode (for those still knowing it from the old collie...).