how to correct map in this situation?

[liuyf5231]

Hi koide3,
I want to know how to correct my points map in this situation? The pillars drift a little in the below picture.

[koide3]

Hi @liuyf5231 ,
In this case, you can add a few manual loop closure constraints to force the doubled pillars to be merged into one, and then refine the pose constraints created by the automatic SLAM. You can also perform automatic loop closing with a large distance threshold to improve the local consistency.

[liuyf5231]

Hi @liuyf5231 ,
In this case, you can add a few manual loop closure constraints to force the doubled pillars to be merged into one, and then refine the pose constraints created by the automatic SLAM. You can also perform automatic loop closing with a large distance threshold to improve the local consistency.

Thanks, I will try it.

[liuyf5231]

Hi @liuyf5231 ,
In this case, you can add a few manual loop closure constraints to force the doubled pillars to be merged into one, and then refine the pose constraints created by the automatic SLAM. You can also perform automatic loop closing with a large distance threshold to improve the local consistency.

Hi koide3,
when I choose two keyframes to make a loop constraint, graph optimization is not performed?! The two pillars are not be merged into one.

[abhi5691]

Hi @liuyf5231 , How did you manage to solve the issue? I am facing a similar challenge. When I add a loop constraint manually, the algorithm simply adds an additional edge between the nodes, leaving them approximately where they were, and hence the map is not really optimized.

See the long edges in top centre and lower center, both pair of nodes are supposed to be much closer together, and were so constrained. What am I missing here?

Any input will help me a lot, thanks.

[ZeyingXuHuaWei]

In this case I think it is better to add a function such that we can do loop closure by picking two 3d points. Anyone know how to achieve this?