LVI-SAM-Easyused

This repository contains modified code of LVI-SAM for easier using.

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Compile

You can use the following commands to download and compile the package.

mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/src
git clone https://github.com/Cc19245/LVI-SAM-Easyused
cd ..
catkin_make

Note：If you want to use the no-modified code (origin LVI-SAM official code), you can change the defination in CMakeLists.txt and compile again.

################## 编译开关 compile switch##############
# -DIF_OFFICIAL=1: use origin official LVI-SAM code
# -DIF_OFFICIAL=0: use modified code of this repo
add_definitions(-DIF_OFFICIAL=0)

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Params config

Sensors extrinsic config

1. params_camera.yaml: set the VIO params, especially for T_imu_camera. It's same as VINS-Mono.

###################### extrinsic between IMU and Camera  ###########################
###################### T_IMU_Camera, Camera -> IMU       ###########################  
# R_imu_camera
extrinsicRotation: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 0,    0,    -1, 
               -1,     0,    0, 
                0,     1,    0]
# t_imu_camera
extrinsicTranslation: !!opencv-matrix
   rows: 3
   cols: 1
   dt: d
   data: [0.006422381632411965, 0.019939800449065116, 0.03364235163589248]

2. params_lidar.yaml: set the LIO params, especially for T_imu_lidar.

  ###################### extrinsic between IMU and LiDAR  ###########################
  ###################### T_IMU_LiDAR, LiDAR -> IMU       ############################
  # t_imu_lidar
  extrinsicTranslation: [0.0,   0.0,   0.0]    
  # R_imu_lidar
  extrinsicRotation: [-1,   0,    0, 
                                         0,    1,    0, 
                                         0,    0,   -1]

IMU property config

Due to the special IMU (the Euler angle coordinate system is different from the angular velocity and angular velocity coordinate system) of official dataset , you also need to set which axis the IMU rotates around counterclockwise to get a positive output. For official sensor equipment, it is set as follows.

  ## 对绝大多数IMU来说，下面三个值分别是"+z", "+y", "+x" (for most of IMUs, the following config is "+z", "+y", "+x")
  # 绕着哪个轴逆时针转动，输出yaw角度为正(which axis the IMU rotates around counterclockwise to get a positive yaw angle)
  yawAxis: "-z"  
  # 绕着哪个轴逆时针转动，输出pitch角度为正(which axis the IMU rotates counterclockwise to get a positive pitch angle)
  pitchAxis: "+x"    
  # 绕着哪个轴逆时针转动，输出roll角度为正(which axis the IMU rotates around counterclockwise to get a positive roll angle)
  rollAxis: "+y"    

==**Note**==: **For most of the IMUs, the Euler angle coordinate system is same as the angular velocity and angular velocity coordinate system**. So the above parameters should be set as follows.

  ## 对绝大多数IMU来说，下面三个值分别是"+z", "+y", "+x" (for most of IMUs, the following config is "+z", "+y", "+x")
  # 绕着哪个轴逆时针转动，输出yaw角度为正(which axis the IMU rotates around counterclockwise to get a positive yaw angle)
  yawAxis: "+z"  
  # 绕着哪个轴逆时针转动，输出pitch角度为正(which axis the IMU rotates counterclockwise to get a positive pitch angle)
  pitchAxis: "+y"    
  # 绕着哪个轴逆时针转动，输出roll角度为正(which axis the IMU rotates around counterclockwise to get a positive roll angle)
  rollAxis: "+x"    

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Run the package on different datasets

1. Official dataset

   • Run the launch file:

     roslaunch lvi_sam run.launch
     

     Note: If you want to test the origin official LVI-SAM code (e.g. set add_definitions(-DIF_OFFICIAL=1) in CMakeLists.txt to compile), you should run launch file as following.

     roslaunch lvi_sam run_official.launch
     

   • Play existing bag files, e.g. handheld.bag:

     rosbag play handheld.bag 
     

   • Results of origin official code (up fig) and our's modified code (down fig) on handheld.bag:

     

     

2. M2DGR dataset

   • Run the launch file:

     roslaunch lvi_sam M2DGR.launch
     

   • Play existing bag files, e.g. gate_01.bag:

     rosbag play gate_01.bag 
     

   • Results of our's modified code on gate_01.bag:

     

3. UrbanNavDataset

   • Run the launch file:

     roslaunch lvi_sam UrbanNavDataset.launch
     

   • Play existing bag files, the params we provided is for UrbanNav-HK-Data20200314. If you use other bag files of UrbanNavDataset, please check if the params need to be changed.

     rosbag play 2020-03-14-16-45-35.bag 
     

   • Results on UrbanNav-HK-Data20200314:

     

4. KITTI Dataset

   • Run the launch file:

     roslaunch lvi_sam KITTI.launch
     

   • Play existing bag files. If you want to use KITTI dataset, you need to get rosbag files firstly. You can get it refer to LIO-SAM/config/doc/kitti2bag. Here we use KITTI_2011_09_26_drive_0084_synced raw data to get rosbag file. The transformed rosbag file can get at this link.

     rosbag play kitti_2011_09_26_drive_0084_synced.bag  
     

   • Results of our's modified code on kitti_2011_09_26_drive_0084_synced.bag:

     

5. My test dataset

   • Run the launch file:

     roslaunch lvi_sam backbag.launch
     

   • Play existing bag files, e.g. backbag.bag:

     rosbag play backbag.bag 
     

   • Results of our's modified code on backbag.bag:

     

   • Results of our's modified code on our self 0117-1525.bag (Device is not same as backbag.bag, so it has another params. However, sorry for privacy issues, this data package can not open source):

     roslaunch lvi_sam ljj.launch
     rosbag play 0117-1525.bag 
     

     

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TODO

• More test on different dataset, e.g. KAIST. However, these datasets' lidar data have no ring information. So LVI-SAM can't run directly. If you want to run on these datasets, you need to modifidy the code to add this information refer to LeGO-LOAM.

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Notes

If you want to know what changes I made and why they make sense, you can refer to my blog: LVI-SAM坐标系外参分析与代码修改，以适配各种数据集.

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Acknowledgement

• Origin official LVI-SAM.