Problem generating map with cartographer

[saxosun]

Hello,
I am trying to map a large environment using cartographer with imu, laser and odometry. The process works fine, even though it is a little bit slow, until the robot, even though it passes more times for the same area, the color of the floor does not change anymore. So the map remains as you see in the image.
I tryied to reduce the resolution without success, so maybe is not a memory problem. Someone could help me to solve this issue.
Thanks
Salvatore

[saxosun]

I believe that the problem is only that the system becomes slower step by step. So at the end of the mapping it needs more time to complete the map.

[jpvaldivia7]

Hi @saxosun,
The map generation with cartographer is a bit slow so do not worry it is not only you. However, you can still configure it to make it a bit faster changing some settings for example the lidar frequency, lidar number of samples, angles, map update time, etc…
Regarding the map update, your map looks fine but if you want to improve it even more you should set that in the cartographer.lua file.
Changing these you can solve that for example:
POSE_GRAPH.optimize_every_n_nodes = 10 – Lower this to increase optimization frequency
TRAJECTORY_BUILDER_2D.submaps.num_range_data = 90 – Adjust the number of range data per submap
MAP_BUILDER.map_publish_period_sec = 1.0 – Publish the map more frequently
TRAJECTORY_BUILDER_2D.submaps.grid_options_2d.resolution = 0.05 – Ensure the map resolution is appropriate

Try to set these values to see if your map improves.

[roalgoal]

Hi @saxosun,

You know, if the map will not change much in that area, that seems like a good map to use. If you want, you can use an image editor like GIMP to just color drop the map and just fill it yourself.

But if your aim is the quality of the mapping (instead of say, successful navigation), then, in addition to what Juanpa said, I would also check if there is something preventing the sensor from mapping, like maybe the lidar can’t return in those areas and therefore it doesn’t update?

• If you start mapping there, do you still have those gaps?
• If you add an object in the map, does the gap fill?