Low obstacles are not added to grid_map

[Myzhar]

Hi Matthieu,

I'm using RTAB-Map with ZED-M on a TurtleBot.
The odometry is generated by an UKF fusing wheels odometry, IMU and ZED odometry.

RTAB-Map generates a good 2D projected map and I can use it for autonomous navigation with costmap_2d, but low obstacles (e.g. a sofa or a box 40 cm high) are not added to the grid_map.

The configuration I'm using is the following: GIST

[matlabbe]

Hi,

Which exactly is the topic shown for the 2d occupancy grid? Is it the global costmap from move_base? Normally, obstacles in /rtabmap/grid_map should match the obstacles in /rtabmap/cloud_obstacles topic. If the global costmap and the grid map published by rtabmap don't match, the problem could come from the costmap configuration. I see that you are using a laser scan topic which doesn't see obstacles under 40 cm. If this scan is used for the costmap updates, it may clear obstacles.

cheers,
Mathieu

[Myzhar]

Hi,

The topic shown for the 2D occupancy grid is the `grid_map` from RTAB-Map.

The laser scan is shown, but it is not used in the obstacle layer, it only uses the 3D pointcloud.
The obstacle layer is integrated in constmap_2d only for the local cost map.

The global costmap has only a static layer (getting map from RTAB-Map) and an inflation layer.

[matlabbe]

Hi,

I reproduced the problem with your parameters (in particular when Grid/RayTracing=true and a 3D local occupancy grid having many empty cells over obstacle cells). I fixed this in this commit. For those using rtabmap binaries, a workaround is to use /rtabmap/octomap_grid topic instead of /rtabmap/grid_map.

cheers,
Mathieu

[Myzhar]

Thank you Matthieu  

[willzoe]

Hi Myzhar,

I'm also using RTAB-Map with ZED on a TurtleBot. But I encountered some problems while mapping.
This is the link to my question: When using rtabmap to build a map, how to fill the blanks in the map and remove objects outside the map?



The map boundaries in this picture look sharp and there are no gaps.

But the map I created looks messy, like this:


Is it because you use `Virtual LaserScan` that the boundaries of the map are clear?

[matlabbe]

Answered here: https://answers.ros.org/question/348011/when-using-rtabmap-to-build-a-map-how-to-fill-the-blanks-in-the-map-and-remove-objects-outside-the-map/