The ndt_omp registration time is unstable.

[tqltech]

When two similar point clouds are registered with a local map, the registration time of the previous frame is 300 ms and that of the next frame is 50 ms. The number of iterations is the same. What is the possible cause? Parameter configuration: Select DIRECT7, the number of CPU cores to 6, number of threads to 12, point cloud downsampling to 0.8 m, and NDT grid resolution to 2.4 m.

Looking forward to a reply! Thank you!