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laboshinl / loam_velodyne

Laser Odometry and Mapping (Loam) is a realtime method for state estimation and mapping using a 3D lidar.
http://wiki.ros.org/loam_velodyne
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Odometrie orientation #134

Closed lchop closed 5 years ago

lchop commented 5 years ago

Hello,

I have an issue with the odometrie orientation. https://www.youtube.com/watch?v=YTCnmP5RBuE The yellow arrow is not pointing in the direction where the robot is going but instead it is "horizontal". I have the same issue here in the following picture with red arrow representing the odom: Screenshot from 2019-04-18 11-38-16 I have correct it applying a PI/2 rotation to the odom message: Screenshot from 2019-04-18 11-48-56

But I am not happy with this fixe. Anyone has experienced this issue ? Is this even an issue ?

YoshuaNava commented 5 years ago

This is due to LOAM using a camera coordinate frame convention. It's described in the author's papers.

If you want to have a quick fix, just rotate the output poses/clouds of LOAM to your desired coord. frame orientation.

For a more elaborate, long term fix you'd need to dive deeper into the code. It performs all the calculations in the camera coordinate frame, so there is quite that would need to be changed.

lchop commented 5 years ago

Hello,

Thank you for your answers. I have read the author's paper, two frames are mentionned, a world frame W and a Laser Frame L. Just to be sure, the camera frame convention is applied to the 3D laser Frame, is that correct ?

YoshuaNava commented 5 years ago

Hello,

Thank you for your answers. I have read the author's paper, two frames are mentionned, a world frame W and a Laser Frame L. Just to be sure, the camera frame convention is applied to the 3D laser Frame, is that correct ?

And to the IMU.