Updating Autoware to support proposed Pointcloud types and Nebula sensor driver

[drwnz]

The current Autoware documentation for sensing design refers to a point type for pointclouds which is not currently in use (point types used by Autoware can be found here.

In addition, there are further proposals for richer point data types here.

TIER IV is also proposing a universal sensor driver which can be added to as required to support as many LiDAR devices as possible, allowing simpler unification of the ROS interface and pointcloud types used: Nebula sensor driver.

It would seem like a good opportunity to add Nebula as the default sensor driver used by Autoware, and at the same time update Autoware to use the new proposed point types. This would require:

• Identifying nodes that will be affected by the change in point types
• Implementing the changes to Autoware point type definitions
• Implementing required changes to all affected nodes
• Modifying dependencies

And probably much more that I am missing.

I'd like to use this discussion to kick off discussion on whether this is a good idea or not, what needs to be done, and what timeline we should aim for. All comments and contributions are most welcome!

[drwnz]

@xmfcx @amc-nu @mojomex we are currently considering whether to use negative angles in the elevation field. Currently, the implementation handles elevation the same was as azimuth with the negative angles being wrapped around (360 + negative elevation angle).
Negative elevation angles may be more intuitive, but would be interested to hear your thoughts on this.

[xmfcx]

I think it should be acceptable. No change needed in they field type definition since it already uses FLOAT32.
But we should denote the range as [-180°,180°].

Also need to be careful that the algorithms can handle negative values too.