ICP failing because too few correspondeces

[skasperski]

Hello,

I am using CSM on master branch to implement an online sequential scan matching. Currently I am experiencing a strange issue, where the ICP starts failing abruptly after working nicely for several hundreds of scans without any visible reason or change in input data. While working with around 500~700 correspondences all the time, it drops to only 20 correspondences. What could be a reason for such a behaviour?

sm_icp: laser_sens has 721/721; laser_ref has 721/721 rays valid
sm_icp:  laser_sens has 721/721; laser_ref has 721/721 rays valid (after removing outside interval [0.000000, 100.000000])
icp: starting at  q0 =  (0.00 mm, 0.00 mm, 0.0000 deg)  
== icp_loop: starting iteration. 0  
    kill_outliers_double: killed 16 correspondences
    icp_outliers: maxPerc 0.900000 error_limit: fix 0.296794 adaptive 0.589670 
    icp_outliers: valid 20/22 (limit: 0.296794) mean error = 0.183793 
  icp_loop: total error: 3.675868  valid 20   mean = 0.183793
  icp_loop: failed: after trimming, only 20 correspondences.
icp: ICP failed for some reason.

Thanks,
Sebastian