nMeasurements < nDof;

[aditdoshi333]

Facing this error a lot of times. Can you please explain why it is happening and what scene it can happen?

Please share some light to solve this issue.

[CharlieV5]

I have encountered this issue too, with the rotating velodyne LiDAR. This often happens in narrow space, maybe . Looking forward to the author's explaining.

[satyajitghana]

The author has removed code for if (nMeasurements < nDof) which was there in FASTLIO2. due to integration with VoxelMap.

[CharlieV5]

The author has removed code for if (nMeasurements < nDof) which was there in FASTLIO2. due to integration with VoxelMap.

Could you tell us where the code for if (nMeasurements < nDof) in Fast-LIO2 can be found? I tried but not see it in the latest version.

[satyajitghana]

You can take a look at this:

PV-LIO/include/IKFoM_toolkit/esekfom/esekfom.hpp

Line 1756 in 494c27f

Eigen::Matrix<scalar_type, Eigen::Dynamic, Eigen::Dynamic> h_x_cur = Eigen::Matrix<scalar_type, Eigen::Dynamic, Eigen::Dynamic>::Zero(dof_Measurement, n);

Actual Code: https://github.com/hku-mars/FAST_LIO/blob/478d436813b966df94fb91dd759f477f1a246296/include/IKFoM_toolkit/esekfom/esekfom.hpp#L890

You can see lot of lines commented out in PV-LIO which were actual parts of FASTLIO2.

Also another thing to note is that, you can actually disable the voxel based mapping in PV-LIO, which will then rely on the IKFoM based method only using IMU, and if you do that it WILL DRIFT! which it shouldn't, given that FASTLIO2 does not drift.