[Research] How to implement zones in Maliput

[Agustin Alba Chicar]

Ask Drake developers about how to correctly create zones, parking spots and other types of checkpoints, etc.

[Agustin Alba Chicar]

@andres_fortier @hidmic apparently Maliput lacks of administrative information, it can only represent geometric forms so checkpoints, parking spots and other type of signals won't have a representation in Maliput. As described on the spec, zones have a perimeter defined and it's a pathless area where a car can drive. However, it can only be entered or exited through the specified perimeter spots. This leads to the case, like this example where a zone is in the middle of a road and if you want to get it, get out, or pass through you have to go to specific locations.

maddog was copied to the discussion, so we will have some insights on how to represent zones if we can or if it should be added to the Maliput's roadmap.

[Andrés Fortier]

Thanks for the write-up and for kicking the question in Slack @agalbachicar !

[Agustin Alba Chicar]

As we don't have support for Zones in Maliput, we are going to create a connection between the entries and the exits of the zone to avoid having gaps there. Therefore we won't have a no escape lane.

Current visualization is:

[Agustin Alba Chicar]

So the RNDF zone now looks like:

A road like logical connections is RNDF is being made from the entry and exit waypoint of the Zone. Basically, from all the waypoints from the perimeter, we calculate the center of it (the mean value of all the coordinates) and then we create a connection for each possible pair of entry-exit waypoint from the perimeter. Each entry or exit from the perimeter is assigned with a tangent. This last vector is just the difference between the center and the waypoint position, but with a normalized module. Also, direction is adjusted depending on the nature of the waypoint.

Just one minor detail, we use the default width for the lanes inside the zone.

Full darpa.rndf can be used now :)