Question about feature sufficiency in a small indoor environment and checking Lidar-IMU synchronization offset

[sakamakiy1234]

Hi,

I'm using LIO-SAM on ROS2 Humble with a Livox Mid360. In a relatively large indoor space (ceiling height 6–10 m, length/width about 40–50 m), I can build a stable map. However, in a smaller indoor environment (ceiling height 3 m, length ~20 m, width ~2 m), the map creation is unstable.

I suspect that there may not be enough feature points for LIO-SAM to work properly in such a small and narrow environment. Is there any way to check how many features are being extracted and to determine if there are enough feature points for stable mapping? Any recommended metrics or diagnostic outputs to confirm the feature sufficiency would be greatly appreciated.

Additionally, when the map creation fails, I sometimes see a message about the Lidar and IMU being out of sync. Is there a built-in way in LIO-SAM to measure or display the synchronization offset between the IMU and Lidar? Or any other recommended method to check whether the timestamp alignment is correct?

Thank you in advance for your help