How to preserve labeled nodes pose coordinates

[akunin]

Hi,
We dont want that during map update nodes that were marked with labels will move/change coordinates.
is there anyway to tell rtbmap/g20 optimizer to keep specific labels/nodes at same place?
 thanks

[matlabbe]

Not why you don't want that, when they move it is because the map errors are corrected, which is good. Forcing arbitrary nodes to stay fixed in g2o (by adding a "global_pose" with current map->base_link pose + very low covariance and set Optimizer/PriorsIgnored to false) would make the optimizer not converging when trying to correct the map errors, thus rejecting any new loop closures. It is like disabling loop closure detection "Kp/MaxFeatures=-1".

[akunin]

Once map is created - users will save required goals with pose coordinates. After map update those coordinates/goals will be wrong so robot wont achieve its goal anymore. So i'm looking for a way to update map features w/o changing poses we had provided to an user earlier.

[matlabbe]

If the robot is moving down a corridor, save a pose x=25, y=2 at the end of the corridor, continue looping around the building then come back to map origin, detecting there is an odometry drift of 2 meters in y axis, has to correct the map so that the psoe x=25, y=2 should be at x=25,y=0 to represent exactly the same location. If we keep x=25, y=2, instead of being in the middle of the corridor, the pose x=25, y=2 could be inside a room just next to it.

If we would change only features to match the new optimized graph but not the poses, the robot could appear to localize in walls.