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Using GPS with KITTI dataset #35
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There are still some unsolved problems in LIO-SAM when a loop is closed or a GPS measurement is received. Any inputs are welcome from the community. |
@TixiaoShan, my use-case requires creating globally correct point cloud maps. I haven't read the code thoroughly. Can you please list down the issues with including GPS measurements and loop closure, so as to keep track of the required changes and improvements? |
Initial misalignment causes the /lio_sam/mapping/path to drift away from /odometry/gps. Further, when GPS data should be added to the pose graph, there is sudden jump in the pose. Hence leading to imperfect global poses. |
You should tune the function that adds GPS factor in mapOptimization.cpp carefully. KITTI dataset doesn't give GPS covariance, so you have to change the threshold to figure out the best settings. When a GPS factor is added, imuPreintegration will be reset and cause a loss of initial guess in updateInitialGuess(). If the vehicle is moving very fast, the scan-matching may fail. You can disable these lines to help this problem. But it's not perfect. I am still trying to figure out solving matching failure when a GPS factor is added. |
This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. |
@Pallav1299 You mentioned that the number of keyframes was different from the KITTI's ground truth. |
@polbolso I didn't try visualizing in TUM or EUROC formats using EVO. I used KITTI format data. With KITTI format you would have to maintain the same number of poses to evaluate relative and absolute pose errors. This issue is solved by using timestamps in TUM format if I am not wrong. I'd suggest converting KITTI format poses to TUM for evaluation |
Thanks @Pallav1299, I managed to combine the produced results with KITTI ground truth through TUM format. However, it seems that there is a clear misalignment issue. Have you experienced something similar? |
I experienced same issue. There is a difference between vehicle axis and yours. You need to change the x y z poses reference to KITTI vehicle setup. |
I am facing problems while setting LIO-SAM with GPS for the KITTI dataset. I am getting a lot of sudden jumps in the output
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The package works fairly well without GPS. I think it's an issue with improper configuration. I seek some help regarding the same.
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