This porject is a VIO based VINS-MONO whithout ROS.Meanwhile, I add a factor about position (GPS) to optimization preventing error divergence. It's a CMAKE project,and you can debug it in Clion. I am a noob.Thank you. the database is euroc http://projects.asl.ethz.ch/datasets/doku.php?id=kmavvisualinertialdatasets if you want to run,you need to modify the config file. if you have some questions please email me grn213331@163.com the gps2.txt is the needed file ，but the program usually do not have gps 。