performance of ouster lidar

[nuyhead-hwang]

I've been running your algorithm using the ouster lidar (OS0-32) and it seems that PointLIO performs worse than FastLIO for trajectory estimation in certain cases.

It doesn't seem to work robustly, especially in narrow scenes (stairs, hallways, etc...).

<--- Result of Fast-LIO --->

<--- Result of Point-LIO --->

Below is the parameters i tested. (I used the same parameters when i tested Fast-LIO)

Can you please confirm what the problem is?

Thank you :)

common:
    lid_topic:  "/os_cloud_node/points"
    imu_topic:  "/os_cloud_node/imu"
    con_frame: false # true: if you need to combine several LiDAR frames into one
    con_frame_num: 1 # the number of frames combined
    cut_frame: false # true: if you need to cut one LiDAR frame into several subframes
    cut_frame_time_interval: 0.1 # should be integral fraction of 1 / LiDAR frequency 
    time_lag_imu_to_lidar: 0.0 # Time offset between LiDAR and IMU calibrated by other algorithms, e.g., LI-Init (find in Readme)
                               # the timesample of IMU is transferred from the current timeline to LiDAR's timeline by subtracting this value

preprocess:
    lidar_type: 3 # 2 #velodyne                # 1 Livox Avia LiDAR
    scan_line: 32 # 32 #velodyne 6 avia
    timestamp_unit: 3           # the unit of time/t field in the PointCloud2 rostopic: 0-second, 1-milisecond, 2-microsecond, 3-nanosecond.
    blind: 0.2

mapping:
    imu_en: true
    extrinsic_est_en: false # for aggressive motion, set this variable false
    imu_time_inte: 0.01 # = 1 / frequency of IMU
    satu_acc: 30.0 # the saturation value of IMU's acceleration. not related to the units
    satu_gyro: 35 # the saturation value of IMU's angular velocity. not related to the units
    acc_norm: 9.81 # 1.0 for g as unit, 9.81 for m/s^2 as unit of the IMU's acceleration
    lidar_meas_cov: 0.1 # 0.01
    acc_cov_output: 500
    gyr_cov_output: 1000 
    b_acc_cov: 0.0001 
    b_gyr_cov: 0.0001 
    imu_meas_acc_cov: 0.1 #0.1 # 2
    imu_meas_omg_cov: 0.1 #0.1 # 2 
    gyr_cov_input: 0.01 # for IMU as input model
    acc_cov_input: 0.1 # for IMU as input model
    plane_thr: 0.1 # 0.05, the threshold for plane criteria, the smaller, the flatter a plane
    match_s: 81
    fov_degree: 180 
    det_range: 50.0
    gravity_align: false # true to align the z axis of world frame with the direction of gravity, and the gravity direction should be specified below
    gravity: [0.0, 0.0, -9.810] # [0.0, 9.810, 0.0] # gravity to be aligned
    gravity_init: [0.0, 0.0, -9.810] # [0.0, 9.810, 0.0] # # preknown gravity in the first IMU body frame, use when imu_en is false or start from a non-stationary state
    extrinsic_T: [0.0, 0.0, 0.0]
    extrinsic_R: [ 1, 0, 0,
                   0, 1, 0,
                   0, 0, 1 ]

odometry: 
    publish_odometry_without_downsample: false

publish:
    path_en: true                 # false: close the path output
    scan_publish_en: true         # false: close all the point cloud output
    scan_bodyframe_pub_en: false  # true: output the point cloud scans in IMU-body-frame

pcd_save:
    pcd_save_en: false
    interval: -1                 # how many LiDAR frames saved in each pcd file; 
                                 # -1 : all frames will be saved in ONE pcd file, may lead to memory crash when having too much frames.

[Joanna-HE]

请问你用的是最新的commit和ubuntu 20.04及以上版本吗？

[Joanna-HE]

在确认是ubuntu20.04及以上后，可以尝试两个办法，一个是把lidar_meas_cov改成0.01，另一个是把最新的commit中的550行的注释去掉。

[nuyhead-hwang]

I'm already using Ubuntu 20.04.

And changing lidar_meas_cov didn't affect the result.

And, you said to uncomment the 550 lines of code, but I don't know exactly which code to uncomment. Is it line 544 in the code below?

https://github.com/hku-mars/Point-LIO/blob/5e0b8bedb5d6f95f905e506df3a26de562d283eb/src/laserMapping.cpp#LL544C10-L544C10

[Joanna-HE]

Firstly, I am sorry that I have used Chinese in the last response, sorry for the inconvenience caused by my incaution.

Then, the code of Point-LIO you are using is not from the most recent commit, my suggestion in the last response is to uncomment the line 550 of the more recent commit of Point-LIO. There are two approaches for us to figure out where the problems are: 1 If there is no trouble, could you please pull the most recent commit of Point-LIO and run the dataset again? If the large drift shows again, try to uncomment the line 550 of the laserMapping.cpp, i.e., "int add_point_size = ikdtree.Add_Points(PointToAdd, true);". 2 You could give me your dataset through google drive or email, and I will figure out the problems.

Best regards,

Dongjiao He

---

寄件者: vislero @.> 寄件日期: 2023年5月18日 下午 02:17 收件者: hku-mars/Point-LIO @.> 副本: @. @.>; Comment @.***> 主旨: Re: [hku-mars/Point-LIO] performance of ouster lidar (Issue #31)

I'm already using Ubuntu 20.04.

And changing lidar_meas_cov didn't affect the result.

And, you said to uncomment the 550 lines of code, but I don't know exactly which code to uncomment. Is it line 544 in the code below?

https://github.com/hku-mars/Point-LIO/blob/5e0b8bedb5d6f95f905e506df3a26de562d283eb/src/laserMapping.cpp#LL544C10-L544C10

— Reply to this email directly, view it on GitHubhttps://github.com/hku-mars/Point-LIO/issues/31#issuecomment-1552500184, or unsubscribehttps://github.com/notifications/unsubscribe-auth/ANJUIXWM5MN2BFVACNSXJ2LXGW5JPANCNFSM6AAAAAAYDPCEQY. You are receiving this because you commented.Message ID: @.***>

[nuyhead-hwang]

I have shared the data to your email. Please kindly check it.

thank you :)

[Joanna-HE]

Hi, please try the newest commit of Point-LIO for your bag. The modification I made is to uncomment the line 550 of the LaserMapping.cpp, to add more points into the ikdtree map.

---

寄件者: vislero @.> 寄件日期: 2023年5月19日 上午 11:12 收件者: hku-mars/Point-LIO @.> 副本: @. @.>; Comment @.***> 主旨: Re: [hku-mars/Point-LIO] performance of ouster lidar (Issue #31)

I have shared the data to your email. Please kindly check it.

thank you :)

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[nuyhead-hwang]

Thank you.

It seems to be running well now.

[hr2894235132]

在确认是ubuntu20.04及以上后，可以尝试两个办法，一个是把lidar_meas_cov改成0.01，另一个是把最新的commit中的550行的注释去掉。

你好，想问一下这个lidar_meas_cov的修改依据是什么呢，有没有什么具体含义嘞。