Lanelet2 ROS Message Design

[gbiggs]

@mitsudome-r

Assumptions:

• All nodes that access to map data should use Lanelet2 library. Although you mentioned about flexibility of using data without lanelet2 library, I think we should access to the map through the library if you don’t have any critical reasons. This would keep us from having similar codes everywhere in Autoware.

If you do not know how the data will be used, you should not make this assumption.

@mitsudome-r

Message data must contain enough information to reconstruct LaneletMap data structure

This places no requirement on the message data itself being in the Lanelets structure.

@mitsudome-r

Message should be flexible enough to be used in different use cases. e.g. message should be able to express custom tags without changing message definition

• Define those use cases.
• Be very careful about allowing custom data in messages. You need to have a strategy in place for ensuring correct behaviour in the face of incorrect data.

@mitsudome-r

Message should be scalable. e.g. It should be able to represent subset of a map.

• Although I agree with this, you need to define why it is necessary so you know exactly what a “subset of a map” means.

@mitsudome-r

Detailed Use Case:

• retrieving traffic light related to current lane
• calculating route to goal from current position
• retrieving crosswalk area
• retrieving intersection information (yield, right of way)
• finding stop lines
• retrieve geometrical subset of map

These are not detailed. I recommend you follow a use case template. It will help you fill out the necessary detail. A good example is the template designed by Alistair Cockburn many years ago. Martin Fowler has also produced one, and I’m sure there are thousands of other templates.

Keep in mind that this is just the start. From your use cases, you will need to derive requirements.