Rotational offset of LIDAR

[MrOCW]

Hi, I have a Ouster1-32 lidar mounted 45 degrees facing northwest whereas my IMU (MTi630 R) is facing north.

Will this set up still work with LIO-SAM? If so, are these the right extrinsics?
extrinsicTrans: [x units in lidar's frame to imu, y units in lidar's frame to imu, z units in lidar's frame to imu]
extrinsicRot:
[0.707, -0.707, 0,
-0.707, 0.707, 0,
0, 0, 1]
extrinsicRPY:
[0.707, -0.707, 0,
-0.707, 0.707, 0,
0, 0, 1]
Thanks!

[grassjelly]

@MrOCW this worked for me https://www.andre-gaschler.com/rotationconverter/

[cacao1987]

@MrOCW have your solved this prolem?

[ArghyaChatterjee]

How did you solve your rotational offset issue? It looks more like you have figured out the transformation from lidar to imu. How did you give a tilt transform from base_link to lidar at the first place (As you mentioned your lidar tilted 45 degrees).

I am also facing the same issue. IF somebody can help, that would be great.

[MrOCW]

I have not solved it. I just mounted the lidar to face forward in the end. Never had issues with my lidar imu tf

[grassjelly]

I could’t get decent results with a rotated IMU. I ended up mounting it the same orientation as the LIDAR and use an identity matrix to define the extrinsics.

[stale]

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.