This is msckf_vio with loop detection and global pose graph optimization
How to run: 1、catkin_make --pkg msckf_vio --cmake-args -DCMAKE_BUILD_TYPE=Release 2、roslaunch msckf_vio msckf_vio_euroc.launch 3、roslaunch msckf_vio msckf_rviz.launch 4、rosbag play /home/yourname/Downloads/MH_05_difficult.bag