Re: rtabmap_ros outdoor 3D mapping

Posted by matlabbe on
URL: http://official-rtab-map-forum.206.s1.nabble.com/rtabmap-ros-outdoor-3D-mapping-tp6104p6351.html

For TF between imu and camera, are the frames in rviz make sense compared to real setup?

The grid parameters can be set in rtabmap.launch with:

args:="--Grid/NormalsSegmentation false --Grid/MaxGroundHeight 0.05"

Note however that this assumes that we are using a ground robot moving on a plane. This would only be used for occupancy grid generation. For 3D point clouds generation (File->Export 3D clouds...) in rtabmapviz or MapCloud in rviz, those parameters won't have any effects.

For the points under the ground, it is because the depth image has wrong disparity when the camera is close to the ground.

For the bending, you can try setting Optimizer/GravitySigma to 0.1 to force the graph to be even more aligned with gravity. Be cautious that if the IMU transform to camera is wrong, it may not correctly align the ground with xy plane.

To avoid large deformation between two poses on graph optimization, you should add covariance to odometry links, this can be done by setting the arguments odom_tf_angular_variance and  odom_tf_linear_variance here to around 0.01 and 0.0004 respectively. Set odom_frame_id to "odom" (well, the odom frame used by zed) to use TF for odometry instead of the topic.

cheers,
Mathieu