Eitan,

After some more hours playing I found that all the pain comes from the
base_local_planner. This is a powerful building block, but it does not
address my needs.

The plan produced by the carrot_planner is looking good all the time and
what I need is not a local planner but something just eating up the
global plan. If there is an obstacle along the global plan than the
robot should stop and after a while with the obstacle in the global
costmap replan and follow the new global plan. After all I am missing
the idea behind the local planner with a perfect global plan and
obstacles also be handled within the global costmap.

Regards
Christian