add a simple GNSS odometer

[ahuazuipiaoliang]

add a simple GNSS odometer that modified based on lio_sam_6axis. I my branch, I only use GNSS for heading initialization.

[ahuazuipiaoliang]

add support for robosense LiDAR pointcloud which contains XYZIRT data.

[ahuazuipiaoliang]

I've already tested with a robosense Helios 16P LiDAR, 6-axis IMU inside CHC CGI-430/410 combined RTK-INS.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[juliangaal]

How come the GPS data remains in the ENU frame, and isn't transformed into the lidar frame?

[ahuazuipiaoliang]

@juliangaal For now, I assume the position of GNSS is exactly at the position of LiDAR frame. I should added a transform between LiDAR and GPS

[zhh2005757]

Why is it GNSS odometer? Are there any advantages for GNSS odometer compared GNSS original measurements?

[ahuazuipiaoliang]

@zhh2005757 the GNSS odometer is only the node that converts LLH coordinates to cartesian coordinates.