What is Route Network Definition File (RNDF) for Self Driving Car
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One of the 4 core parts of a self Driving Car Software stack is Planning. And RNDF or Route Network Definition File is the first thing PLANNING uses.
An RNDF is a tab-delimited ASCII file. It basically defines the Roadsegments and Zones.
The typical format of an RNDF file looks like the following.
RNDF_name filename (string)
num_segments number_of_segments (integer>0)
num_zones number_of_zones (integer≥ 0)
format_version format_version (string)
creation_date creation_date (string)
<segment 1>
.
.
<segment M>
<zone M+1>
.
.
<zone M+N>
end_file
Just looking at the format, we can clearly see that the RNDF file contains details about segments and zones. Here is an example of the road segment
Now let’s look at the format of each segment. It should start making sense now
segment segment_id (integer>0)
num_lanes number_of_lanes (integer>0)
segment_name segment_name (string)
<lane 1>
.
.
<lane n>
end_segment
But it is not complete Just looking at Figure 1, we see that more information need to be defined. Like the lane_width provides the width of the lane in feet. We also need to define the number of waypoints and their location. We need checkpoint which indicates that the waypoint is a named checkpoint. The keyword stop indicates a waypoint associated with a stop sign. The keyword exit is followed by the name of the exit_waypoint and related entry_waypoint or entry_perimeterpoint associated with the lane. A lane may have multiple checkpoints, stop signs, entry waypoints, entry perimeter points, or exit waypoints. Here you go:
lane lane_id (x.y; x,y∈ integer>0)
num_waypoints number_of_waypoints (integer>0)