Tunnel recognition

Hi ,

I'm looking for an improvement in the algorithm regarding the recognition of tunnels.

My concern is, that I have several tracks, where a tunnel has nearly the same geometry as a surface road. In these situations the matching is often wrong and leeds to really ugly routings:

Shown in green is the correct way through the tunnel and red is the surface routing, which BF prefers ...

Now I have to make two changes:

1. Extend the road class with a tunnel flag and fill it from the original map
2. Extend the calculation of emission probabilities

First point is trival, but the second is puzzling me. A simple assumption is, that if I have a GPS measurement the tracker cannot be in a tunnel. But this of course is to simple as the tunnel can be very short or the ramps down in and up from the tunnel are modelled as tunnel, but has still have good satellite signal.

I have made some promissing experiments in changing the minimize function of road point candidates or in decreasing the emission propability of road points. But overall I'm unsure about a robust solution ...

Have you thought about this or have you ad hoc any good ideas on a solution for this?

BR Volker

该提问来源于开源项目：bmwcarit/barefoot