[Proposal] Change the default input_pointcloud topic for localization component

[TaikiYamada4]

Proposal

Change the default input_pointcloud argument in autoware_launch/launch/components/tier4_localization_component.launch.xml
from /sensing/lidar/top/pointcloud to /sensing/lidar/concatenated/pointcloud.

Background and reasons

Thanks to the contributions of everyone involved, Autoware has become widely used by many users and vehicles. Since various types of vehicles have been applied to Autoware, I'd like to discuss about the input pointcloud of the localization component to use the concatenated pointcloud rather than a single-LiDAR pointcloud. There are two main reasons.

1. Not all vehicles have a "top" LiDAR, and there are some vehicle designs like large buses that needs multiple LiDARs to capture the entire surroundings. Therefore, I am expecting that using /sensing/lidar/concatenated/pointcloud as a default may be more applicable to various vehicle designs.
2. Due to the incoming changes of the pointcloud preprocessing, /sensing/lidar/top/pointcloud will be a synchronized pointcloud with other LiDARs. Hence, the difference between /sensing/lidar/top/pointcloud and /sensing/lidar/concatenated/pointcloud is just about how many LiDARs are involved to the pointcloud, and generally the more points we have the more accurate the localization will be.

Note that this is just a change of the default input pointcloud and doesn't mean that the localization component doesn't receive a pointcloud from a single LiDAR, but you have to rewrite the addressing part instead.

When?

If there are no problems or concerns of this modification found, I'd like to throw a PR of this change next Wednesday (Feb. 21st).

I am looking forward to hearing comments or concerns about this proposal from you!

[yukkysaito]

I agree with this proposal 👍

[TaikiYamada4]

Here are the related PRs!!

• feat(tier4_localization_component_launch): change the default input pointcloud of localization into the concatenated pointcloud autoware_launch#899
• feat(tier4_localization_launch): change the default input pointcloud of localization into the concatenated pointcloud autoware.universe#6528

[TaikiYamada4]

These PRs have been successfully merged.
Thank you for your support! ❤️