Stereo Mpping in the streets

[Alexia]

Hello

We have a question regarding the terrain the robot has to dive through. As we're using a stereo camera we assume that the occupancy grid is based on texture and colour. So in case we're driving on the sidewalk and the robot needs to cross at a crossroads, will it map the white stripes as obstacles? And if that is the case, is there a way to tell it not to map it?

The sidewalk will look something like this:

And the crosswalk:


And what in case the sidewalk has been recently wet and some places are dry like this:


And lastly, if there is an object we need to go pick up, is there a way to make sure it isn't marked as an obstacle?

Best regards
Alexia

[matlabbe]

Hi Alexia,

obstacles with stereo cameras are done exactly the same as with RGB-D cameras, geometry is used, not texture. In your three examples, rtabmap won't see obstacles. If so, it is because of some noise in camera's disparity that would add points over the ground.

An object to pickup will be detected as an obstacle, which is correct if we think about navigation only as we don't want to hit it. You may have to send yourself cmd_vel to your robot (bypassing move_base that uses costmaps) to move over the obstacle (if you detected it as an object to pickup). Other way could be to clear the obstacle in the costmaps before move_base plans a trajectory.

cheers,
Mathieu