Run big-loop.bag data set with different results about lio-sam

[TixiaoShan]

The loop closure results come from PCL icp. Sometimes ICP gives bad results. A more advanced loop closure can be found here.
https://github.com/irapkaist/SC-LeGO-LOAM

[windwolf9]

Thanks,and I found that the loop closure is good In the beginning()，and it will going to get worse immediately and an error occurs :[ WARN] [1594800092.012221229]: Large velocity, reset IMU-preintegration! When it happened，then the maps got worse。
The results are as follows：

[TixiaoShan]

The current implementation of loop closure is not ideal. The success rate heavily depends on the performance of PCL icp.

[TixiaoShan]

A better implementation is welcome from the community.
Feel free to join and discuss how to improve its performance.

[TixiaoShan]

A better implementation is welcome from the community.
Feel free to join and discuss how to improve its performance.

Loop closure should be fixed now.