I have a few questions about setting up the navigation stack. I have a very simple simulator node which broadcasts Odometry messages and consumes Twist messages. Using a GUI program, I've been able to monitor and verify the performance of this node.

Assuming that for the purposes of getting started, I don't (yet) care about mapping or obstacle-avoidance, is this simulation enough to run the navigation stack?

I've followed the tutorials as best I can, but of course I haven't got a map, so map_server fails to start, and then move_base gives this warning: 

This is expected, as I have not broadcasted any tf transforms. But my robot has no joints or geometric parts, so there's nothing to broadcast---as far as the simulator is concerned, it's just a box on wheels. Is there a way to make the base_link frame exist independent of using a tf::TransformBroadcaster to broadcast its relationship to another frame?

Further to that, how do I address the larger map issue? Can I disable the mapping functionality somehow (for now), or should I just create a blank map and let it use that?

Is my objective completely unreasonable, or is this just a matter of some configuration tweaks?

Thanks in advance for any suggestions or guidance,

Mike