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hku-mars / LTAOM

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Multi-session mode question #7

Open wolf943134497 opened 2 months ago

wolf943134497 commented 2 months ago

@zuhaozou2017 Thanks for your great works! I have a question about the multi session mode:

If the two dataset only have some overlap at the middle moment, there is no overlapping area at other times. Is LTAOM suitable for this scenario? and merge 2 maps into one large map containing all areas. Thanks!

zuhaozou2017 commented 2 months ago

I think the answer is "yes". LTAOM will automatically do relocalization once it enters the overlapping area.

wolf943134497 commented 2 months ago

@zuhaozou2017 Thanks for your rapid reply!
LTAOM will automatically do relocalization once it enters the overlapping area, so if I want to merge 2 maps into one large map containing all areas, the prior submap pose must be global pose (gps info) and LIO also have global pose or LTAOM estimate two path coordinate transformation, otherwise the second path will discard the map before encountering the overlapping area. Is my understanding correct? Thanks！

zuhaozou2017 commented 2 months ago

global pose means last session's keyframe poses. Of course, you can do some gps fusion coding.

"otherwise the second path will discard the map before encountering the overlapping area" - No, two sessions' maps will just be what they like in the single session mode, i.e., not consistent overlapping.

wolf943134497 commented 2 months ago

global pose means last session's keyframe poses. Of course, you can do some gps fusion coding.

"otherwise the second path will discard the map before encountering the overlapping area" - No, two sessions' maps will just be what they like in the single session mode, i.e., not consistent overlapping.

It means the multisession map is inconsistent in overlapping areas? the map diff depending on each session pose accuracy. when LTAOM do relocalization in the overlapping area, the second session will not do mapping and the coordinate of the second session map will convert to first session map？ Another great job from your team HBA can solve the not consistent overlapping map problem? Thanks

zuhaozou2017 commented 2 months ago

"It means the multisession map is inconsistent in overlapping areas? the map diff depending on each session pose accuracy. when LTAOM do relocalization in the overlapping area, the second session will not do mapping and the coordinate of the second session map will convert to first session map？" - totally opposite, multisession map is consistent in overlapping areas. relocalization will make coordinate 2 -> 1.

"Another great job from your team HBA can solve the not consistent overlapping map problem? Thanks" - yes

wolf943134497 commented 2 months ago

"It means the multisession map is inconsistent in overlapping areas? the map diff depending on each session pose accuracy. when LTAOM do relocalization in the overlapping area, the second session will not do mapping and the coordinate of the second session map will convert to first session map？" - totally opposite, multisession map is consistent in overlapping areas. relocalization will make coordinate 2 -> 1.

"Another great job from your team HBA can solve the not consistent overlapping map problem? Thanks" - yes

Thanks for your patient answer and great paper&codes. Thanks

wolf943134497 commented 2 months ago

@zuhaozou2017 Sorry to bother you again, If I have more than two data to merge like 3-4, The output of LTAOM is 3-4 map and keyframe pose like in single session mode，all the map and pose in the first data Coordinate? Thanks